Semiconductor device and peeling off method and method of manufacturing semiconductor device

ABSTRACT

The present invention provides a peeling off method without giving damage to the peeled off layer, and aims at being capable of peeling off not only a peeled off layer having a small area but also a peeled off layer having a large area over the entire surface at excellent yield ratio. The metal layer or nitride layer  11  is provided on the substrate, and further, the oxide layer  12  being contact with the foregoing metal layer or nitride layer  11  is provided, and furthermore, if the lamination film formation or the heat processing of 500° C. or more in temperature is carried out, it can be easily and clearly separated in the layer or on the interface with the oxide layer  12  by the physical means.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method of peeling off a peeled offlayer, particularly, relates to a method of peeling off a peeled offlayer containing a variety of elements. In addition, the presentinvention relates to a semiconductor device having a circuit consistedof a thin film transistor (hereinafter, referred to as TFT) in which thepeeled off layer peeled off has been pasted and transferred on a basemember and a method of manufacturing the semiconductor device. Forexample, the present invention relates to an electro-optic device whichis represented by a liquid crystal module, alight emitting device whichis represented by an EL module and an electronic equipment on which sucha device is mounted as a part.

It should be noted that in the present specification, the term“semiconductor device” indicates a device in general capable offunctioning by utilizing the semiconductor characteristics, and anelectro-optic device, alight emitting device, a semiconductor circuitand an electronic equipment are all semiconductor device.

2. Related Art

In recent years, a technology constituting a thin film transistor (TFT)using a semiconductor thin film (in the range from about a few to a fewhundreds nm in thickness) formed on the substrate having an insulatingsurface has drawn the attention. A thin film transistor is widelyapplied to electronic devices such as an IC, an electro-optic device orthe like, and particularly, there is an urgent need to be developed as aswitching element for an image display device.

Although as for applications utilizing such an image display device, avariety of applications are expected, particularly, its utilization forportable apparatuses has drawn the attention. At present, although manyglass substrates and quartz substrates are utilized, there are defaultsof being easily cracked and heavy. Moreover, the glass substrates andquartz substrates are difficult to be made larger on the basis ofmass-production, and these are not suitable for that. Therefore, theattempt that a TFT element is formed on a substrate having flexibility,representatively, on a flexible plastic film has been performed.

However, since the heat resistance of a plastic film is low, it cannothelp lowering the highest temperature of the process. As a result, atpresent, a TFT is formed which has not so excellent electriccharacteristics compared with those formed on the glass substrates.Therefore, a liquid crystal display device and light emitting elementhaving a high performance by utilizing a plastic film have not beenrealized yet.

Moreover, a method of peeling off a peeled off layer existing on thesubstrate via an isolated layer from the foregoing substrate has beenalready proposed. For example, technologies described in JapaneseUnexamined Patent Publication No. H10-125929 gazette and JapaneseUnexamined Patent Publication No. H10-125931 gazette are technologiesthat an isolated layer consisted of an amorphous silicon (orpolysilicon) is provided, a laser beam is irradiated by transmitting thesubstrate and makes hydrogen contained in the amorphous siliconreleased, thereby occurring a space-gap and separating the substrate. Inaddition, there also has been the description in Japanese UnexaminedPatent Publication No. H10-125930 gazette that by utilizing thistechnology, a liquid crystal display device is completed by pasting apeeled off layer (in the gazette, referred to as transferred layer) on aplastic film.

However, in the above-described method, it is essential to use asubstrate having a high translucency, and further, for the purpose ofconferring a sufficient energy for releasing hydrogen contained in theamorphous silicon, the irradiation of a comparatively large laser beamis necessary, and consequently a problem that the peeled off layer isdamaged occurred. Moreover, in the above-described method, in the casewhere an element is prepared on an isolated layer, if a heat processingat a high temperature or the like is performed in the process of elementpreparation, hydrogen contained in the isolated layer is dispersed andreduced. In that case, even if the laser beam is irradiated on theisolated layer, there is a possibility that the peeling off is notsufficiently performed. Therefore, in order to maintain the amount ofhydrogen contained in the isolated layer, a problem occurs that theprocesses after the isolated layer formation are limited. Moreover, inthe above-described gazette, there has been also the description that inorder to prevent the damage to the peeled off layer, a radiation shieldlayer or a reflection layer is provided. However, in this case, it isdifficult to prepare a transmitting type liquid crystal display device.In addition, by the above-described method, it is difficult to peel offa peeled off layer having a large area.

SUMMARY OF THE INVENTION

The present invention has been carried out in consideration of theabove-described problems, the present invention provides a peeling offmethod of peeling off the peeled off layer without damaging the peeledoff layer, and aims at being capable of peeling off entirely over thesurface of the peeled off layer having a large area as well as peelingoff a peeled off layer having a small area.

Moreover, the present invention aims at providing a peeling off methodof peeling off without receiving the limitations such as the heatingprocessing temperature, the kind of substrate or the like in theformation of the peeled off layer.

Moreover, the present invention aims at providing a semiconductor deviceweight-saved by pasting a peeled off layer on a variety of base membersand its method of preparing it. Particularly, the present invention aimsat providing a semiconductor device weight-saved by pasting a variety ofelements (thin film diode, photoelectric conversion element consisted ofPIN junction of silicon) and its method of preparing it. When thepresent inventors carried out many experiments and considered aboutthese, the present inventors have found that during the time when thepresent inventors provided an nitride layer provided on the substrate,preferably a metal nitride layer, an oxide layer being in contact withthe foregoing metal nitride layer, and further performed the filmformation or the heat processing at the temperature of 500° C. or moreon an oxide layer, the abnormality on the processes such as a filmpeeling or the like does not occur, whereas the present inventors havefound a peeling off method in which it can be easily and clearlyseparated on the oxide layer or interface between them by adding aphysical force, representatively, a mechanical force (for example,peeled off by human hands).

Specifically, the bonding force between nitride layer and oxide layerhas a strength durable for heat energy, whereas since the film stress ofthe nitride layer and the oxide layer is different from each other andthere exists a stress distortion between the nitride layer and the oxidelayer, dynamical energy is weak, it is suitable for peeling off. Thepresent inventors refer to the peeling off step in which the peeling offis carried out by utilizing the film stress in that manner as a stresspeeling off process.

It should be noted that in the present specification, the internalstress of the film (referred to as film stress) is a force per unitsectional area where one side of the section has an influence on theother side, when a given section in the internal of the film formed onthe substrate is considered. The internal stress may always exist moreor less in a thin film formed by a vacuum deposition, a sputtering, avapor deposition method or the like. The value reaches 10⁹ N/m² at themaximum. The internal stress value changes by a material of a thin film,substance of the substrate, the formation conditions of the thin filmand the like. Moreover, the internal stress value changes also byperforming the heat processing.

Moreover, in the case where the force having an influence on theopponent through the unit sectional area which spread out vertically inrespect to the substrate surface works in the tensile direction, it isreferred to as tensile state, and the internal stress at that time isreferred to as the tensile stress. In the case where the force works inthe pushing direction, it is referred to as in a compressive state, andthe internal stress at that time is referred to as compressive stress.It should be noted that in the present specification, the tensile stressis plotted as a positive (+) number, and the compressive stress isplotted as a negative (−) number when these are graphed or indicated ina table.

The constitution 1 of the invention related to a peeling off methoddisclosed in the present specification, is a peeling off method ofpeeling off a peeled off layer from a substrate,

it is characterized by the fact that on the foregoing substrate, anitride layer is provided, after a peeled off layer consisted of alamination containing an oxide layer being in contact with at least theforegoing nitride layer was formed on the substrate on which theforegoing nitride layer has been provided, the relevant peeled off layeris peeled off on the inside of the oxide layer or on the interface withthe foregoing oxide layer from the substrate on which the foregoingnitride layer has been provided by the physical means.

Moreover, it may be peeled off after a support body was adhered using anadhesive agent, the constitution 2 of the invention related to a peelingoff method disclosed in the present specification,

-   -   is a peeling off method of peeling off a peeled off layer from a        substrate,        it is characterized by the fact that on the foregoing substrate,        a nitride layer is provided, after a peeled off layer consisted        of a lamination containing an oxide layer being in contact with        at least the foregoing nitride layer was formed on the substrate        on which the foregoing nitride layer has been provided and the        relevant peeled off layer adhered to the foregoing supporting        body is peeled off on the inside of the oxide layer or on the        interface with the foregoing oxide layer from the substrate on        which the foregoing nitride layer has been provided by the        physical means.

Moreover, in the above-described constitution 2, in order to promote thepeeling off, the heat processing or the irradiation of a laser beam maybe performed before the foregoing supporting body is adhered. In thiscase, it may be made so as to be easily peeled off by selecting amaterial absorbing the laser beam and heating the interface between thenitride layer and the oxide layer. However, in the case where the laserbeam is used, a translucent one is used as a substrate.

Moreover, in the above-described constitution, as for the nitride layer,the other layer may be provided between the substrate and the nitridelayer, for example, an insulating layer, a metal layer or the like maybe provided. However, in order to simplify the process, it is preferredthat the nitride layer being in contact with the surface of thesubstrate is formed.

Moreover, instead of the nitride layer, a metal layer, preferably anitride metal layer may be used, a metal layer, preferably a metalnitride layer is provided, and further, an oxide layer is provided incontact with the foregoing metal nitride layer, and further, if the filmformation processing or the heat processing of 500° C. or more intemperature is carried out, the film peeling does not occur, it can beeasily and clearly separated on the inside of the oxide layer or on theinterface with the oxide layer by the physical means.

The constitution 3 of the invention related to a peeling off methoddisclosed in the present specification, is a method of peeling off apeeled off layer from a substrate,

it is characterized by the fact that on the foregoing substrate, a metallayer is provided, after a peeled off layer consisted of a laminationcontaining an oxide layer being in contact with at least the foregoingmetal layer was formed on the substrate on which the foregoing metallayer has been provided, the relevant peeled off layer is peeled off onthe inside of the foregoing oxide layer or on the interface with theoxide layer from the substrate on which the foregoing metal layer hasbeen provided by the physical means.

Moreover, it may be peeled off after the supporting body was adheredusing an adhesive, the constitution 4 of the invention related to apeeling off method disclosed in the present specification,

-   -   is a method of peeling off a peeled off layer from a substrate,        and        it is characterized by the fact that on the foregoing substrate,        a metal layer is provided, after a peeled off layer consisted of        a lamination containing an oxide layer being in contact with at        least the foregoing metal layer was formed on the substrate on        which the foregoing metal layer has been provided, the peeled        off layer adhered to the foregoing supporting body is peeled off        on the inside of the foregoing oxide layer or on the interface        with the oxide layer from the substrate on which the foregoing        metal layer has been provided by the physical means.

Moreover, in the above-described constitution 4, in order to promote thepeeling off, the heat processing or the irradiation of a laser beam maybe performed before the foregoing supporting body is adhered. In thiscase, it may be made so as to be easily peeled off by selecting amaterial absorbing the laser beam and heating the interface between themetal layer and the oxide layer. However, in the case where the laserbeam is used, a translucent one is used as a substrate.

It should be noted that in the present specification, the physical meansis referred to a means recognized by physics, not by chemistry,concretely, the term indicates a dynamic means or a mechanical meanshaving a process capable of attributing to the laws of dynamics and alsoindicates a means for changing any dynamic energy (mechanical energy).

However, in either of the above-described constitution 2 andconstitution 4, when these are peeled off by the physical means, it isrequired so that the bonding force between the oxide layer and the metallayer is made smaller than the bonding force with the supporting body.Moreover, in the above-described constitution 3 or constitution 4, theforegoing metal layer is characterized by the fact that it is an elementselected from Ti, Al, Ta, W, Mo, Cu, Cr, Nd, Fe, Ni, Co, Zr, Zn, Ru, Rh,Pd, Os, Ir and Pt, a monolayer consisted of alloy materials or compoundmaterials whose principal component is the foregoing element, or alamination of these metals or a mixture of these.

Moreover, in the above-described constitution 3 or constitution 4, asfor the metal layer, the other layer, for example, an insulating layeror the like may be provided between the substrate and the metal layer,but in order to simplify the process, it is preferable that the metallayer being in contact with the surface of the substrate is formed.

Moreover, in the above-described present invention, all kinds ofsubstrates, not limited to a substrate having a translucency, forexample, a glass substrate, a quartz substrate, a semiconductorsubstrate, a ceramic substrate, a metal substrate can be used, and apeeled off layer provided on the substrate can be peeled off. Moreover,in the above-described respective constitutions, the foregoing oxidelayer is characterized by the fact that it is a monolayer consisted ofsilicon oxide material, or metal oxide material or lamination of these.

Moreover, in the above-described respective constitutions, in order topromote the peeling off, the heat processing or the irradiation of alaser beam may be performed before the peeling off is performed by theforegoing physical means.

Moreover, a semiconductor device can be fabricated by pasting(transferring) a peeled off layer provided on the substrate on thetransferring body using a peeling of method of the above-describedpresent invention, the constitution of the invention related to a methodof manufacturing a semiconductor device,

is a method of manufacturing a semiconductor device characterized by thefact that it has the steps of,forming a nitride layer on a substrate,forming an oxide layer on the foregoing nitride layer,forming an insulating layer on the foregoing oxide layer,forming an element on the foregoing insulating layer,peeling off the relevant supporting body on the inside of the oxidelayer or on the interface with the foregoing oxide layer from thesubstrate by the physical means after the supporting body was adhered tothe foregoing element, andadhering a transferring body to the foregoing insulating layer or theforegoing oxide layer, and sandwiching the foregoing element between theforegoing supporting body and the foregoing transferring body.

Moreover, in the above-described constitution, in order to promote thepeeling off, the heat processing or the irradiation of a laser beam maybe performed before the foregoing supporting body is adhered. In thiscase, it may be made so as to be easily peeled off by selecting amaterial for absorbing the laser beam for the nitride layer and heatingthe interface between the nitride layer and the oxide layer. However, inthe case where the laser beam is used, a translucent one is used as asubstrate. Moreover, in order to promote the peeling off, it may be madeso as to be easily peeled off by providing an oxide in a granular shapeon the nitride layer, an oxide layer for covering the relevant oxide ina granular shape, the constitution of the invention related to a methodof manufacturing a semiconductor device,

is a method of preparing a semiconductor device, characterized by thefact that it has the steps of,forming a nitride layer on a substrate,forming an oxide in a granular shape on the foregoing nitride layer,forming an oxide layer for covering the foregoing oxide on the foregoingnitride layer,forming an insulating layer on the foregoing oxide layer,forming an element on the foregoing insulating layer,peeling off the relevant supporting body on the inside of the oxidelayer or on the interface with the foregoing oxide layer from thesubstrate by the physical means after the supporting body was adhered tothe foregoing element, andadhering a transferring body to the foregoing insulating layer or theforegoing oxide layer, and sandwiching the foregoing element between theforegoing supporting body and the foregoing transferring body.

Moreover, the constitution of the invention related to a method ofpreparing the other semiconductor device, is a method of manufacturing asemiconductor device, characterized by the fact that it has the stepsof, forming a layer containing a metal material on a substrate,

forming an oxide layer on the foregoing layer containing the metalmaterial,forming an insulating layer on the foregoing oxide layer,forming an element on the foregoing insulating layer,peeling off the relevant supporting body on the inside of the oxidelayer or on the interface with the foregoing oxide layer from thesubstrate by the physical means after the supporting body was adhered tothe foregoing element, andadhering a transferring body to the foregoing insulating layer or theforegoing oxide layer, and sandwiching the foregoing element between theforegoing supporting body and the foregoing transferring body.

Moreover, in the above-described constitution, in order to promote thepeeling off, the heat processing or the irradiation of a laser beam maybe performed before the foregoing supporting body is adhered. In thiscase, it may be made so as to be easily peeled off by selecting amaterial absorbing the laser beam for the metal layer and heating theinterface between the metal layer and the oxide layer. However, in thecase where the laser beam is used, a translucent one is used as asubstrate. Moreover, in order to promote the peeling off, it may be madeso as to be easily peeled off by providing an oxide in a granular shapeon a layer containing a metal material and an oxide layer for coveringthe relevant oxide in a granular shape, the constitution of theinvention related to a method of manufacturing a semiconductor device,

is a method of manufacturing a semiconductor device, characterized bythe fact that it has the steps of,forming a layer containing a metal material on a substrate,forming an oxide in a granular shape on the foregoing layer containingthe metal material,forming an oxide layer for covering the foregoing oxide,forming an insulating layer on the foregoing oxide layer,forming an element on the foregoing insulating layer,peeling off the relevant supporting body on the inside of the oxidelayer or on the interface with the foregoing oxide layer from thesubstrate by the physical means after the supporting body was adhered tothe foregoing element, andadhering a transferring body to the foregoing insulating layer or theforegoing oxide layer, and sandwiching the foregoing element between theforegoing supporting body and the foregoing transferring body.

In the above-described constitution, it is preferable that the foregoinglayer containing the metal material is a nitride, the foregoing metalmaterial is characterized by the fact that it is an element selectedfrom Ti, Al, Ta, W, Mo, Cu, Cr, Nd, Fe, Ni, Co, Zr, Zn, Ru, Rh, Pd, Os,Ir and Pt, a monolayer consisted of alloy materials or compoundmaterials whose principal component is the foregoing element, or alamination of these metals or a mixture of these.

Moreover, a semiconductor device can be prepared by pasting a peeled offlayer provided on the substrate on the first transferring body or thesecond transferring body using a method of peeling off of theabove-described present invention, the constitution of the inventionrelated to a method of manufacturing a semiconductor device,

is a method of manufacturing a semiconductor device characterized by thefact that it has the steps of,forming a layer containing a metal material on a substrate,forming an oxide in a granular shape on the foregoing layer containingthe metal material,forming an insulating layer on the foregoing oxide layer,forming an element on the foregoing insulating layer,peeling off on the inside of the oxide layer or on the interface withthe foregoing oxide layer from the substrate by the physical means,adhering the first transferring body to the foregoing insulating layeror the foregoing oxide layer, and adhering the second transferring bodyto the foregoing element and sandwiching the foregoing element betweenthe foregoing first transferring body and the foregoing secondtransferring body.

In the above-described constitution, it is preferable that the foregoinglayer containing the metal material is a nitride, the foregoing metalmaterial is characterized by the fact that it is an element selectedfrom Ti, Al, Ta, W, Mo, Cu, Cr, Nd, Fe, Ni, Co, Zr, Zn, Ru, Rh, Pd, Os,Ir and Pt, a monolayer consisted of alloy materials or compoundmaterials whose principal component is the foregoing element, or alamination of these metals or a mixture of these.

Moreover, the constitution of the invention related to a method ofpreparing the other semiconductor device, is a method of manufacturing asemiconductor device characterized by the fact that it has the steps of,

forming a nitride layer on a substrate,forming an oxide layer on the foregoing nitride layer,forming an insulating layer on the foregoing oxide layer,forming an element on the foregoing insulating layer,peeling off on the inside of the oxide layer or on the interface withthe foregoing oxide layer from the substrate by the physical means,adhering the first transferring body to the foregoing insulating layeror the foregoing oxide layer, and adhering the second transferring bodyto the foregoing element and sandwiching the foregoing element betweenthe foregoing first transferring body and the foregoing secondtransferring body.

Moreover, in the above-described respective constitutions related to amethod of manufacturing the above-described semiconductor device, theforegoing oxide layer is characterized by the fact that it is amonolayer consisted of a silicon oxide material or a metal oxidematerial or a lamination of these.

Moreover, in the above-described respective constitutions related to amethod of preparing the above-described semiconductor device, in orderto further promote the peeling off, the heating processing or theirradiation of laser beam may be performed before the peeling off isperformed by the foregoing physical means.

Moreover, in the above-described respective constitutions related to amethod of manufacturing the above-described semiconductor device, theforegoing element is characterized by the fact that it is a thin filmtransistor comprising a semiconductor layer as an active layer, the stepof forming the foregoing semiconductor layer is a step in which asemiconductor layer having an amorphous structure is crystallized byperforming the heat processing or the irradiation of a laser beam, andmaking it a semiconductor layer having a crystalline structure.

It should be noted that in the present specification, the term“transferring body” is one for being adhered to the peeled layer afterit was peeled off, is not particularly limited, and may be a base memberof any component such as plastic, glass, metal, ceramics or the like.Moreover, in the present specification, the term “supporting body” maybe one for being adhered to the peeled layer when it is peeled off bythe physical means, is not particularly limited, may be a base member ofany component such as plastics, glass, metal, ceramics, or the like.Moreover, the shape of the transferring body and the shape of thesupporting body are neither particularly limited, and may be one havinga plane, one having a curved surface, one having a surface capable ofbeing curved, or one in a film shape. Moreover, if the weight saving isthe top priority, it is preferable that it is a plastic substrate in afilm shape, for example, polyethylene terephthalate (PET), polyethersulfone (PES), polyethylene naphthalate (PEN), polycarbonate (PC),nylon, polyether ether ketone (PEEK), polysulfone (PSF), polyether imide(PEI), polyarylate (PAR), polybutylene terephthalate (PBT), polyimide orthe like. In the above-described respective constitution related to amethod of manufacturing the above-described semiconductor device, in thecase where a liquid crystal display device is prepared, the supportingbody is made as an opposing substrate, the supporting body may beadhered to the peeled off layer by utilizing a sealing member as anadhesive member. In this case, an element provided on the foregoingpeeled off layer has a pixel electrode, and it is made so that a liquidcrystal material is packed between the relevant pixel electrode and theforegoing opposing substrate.

Moreover, in the above-described respective constitution related to amethod of preparing the above-described semiconductor device, in thecase where a light emitting device represented by a light emittingdevice having an OLED is prepared, it is preferable that a lightemitting element is completely interrupted from the external so as toprevent substances such as water content, oxygen or the like whichpromotes the deterioration of an organic compound layer from penetratingfrom the external. Moreover, if the weight saving is the top priority,it is preferable that a plastic substrate in a film shape is used.However, since it is weak in an effect to prevent substances such aswater content, oxygen or the like promoting the deterioration of theorganic compound layer from penetrating from the external, it may beconfigured, for example, so that it sufficiently prevents substancessuch as water content, oxygen or the like promoting the deterioration ofthe organic compound layer from penetrating from the external byproviding the first insulating film, the second insulating film and thethird insulating film on the supporting body. However, the foregoingsecond insulating film (stress relaxation) sandwiched between theforegoing first insulating film (barrier film) and the foregoing thirdinsulating film (barrier film) is made so that its film stress issmaller than those of the foregoing first insulating film and theforegoing third insulating film.

Moreover, in the case where a light emitting device represented by alight emitting device having an OLED is prepared, it is preferable thatthe invasion of substances such as water content, oxygen, or the likefrom the external is sufficiently prevented by providing the firstinsulating film, the second insulating film and the third insulatingfilm not only on the supporting body but also similarly on thetransferring body.

(Experiment 1)

Here, an oxide layer being in contact with a nitride layer or a metallayer was provided, and in order to verify whether or not a peeled layercould be peeled off from the substrate, the following experiment wascarried out.

First, a lamination as indicated in FIG. 3A was formed on the substrate.

As a substrate 30, a glass substrate (#1737) was used. Moreover, on thesubstrate 30, an aluminum-silicon alloy layer 31 was formed in thicknessof 300 nm by a sputtering method. Subsequently, a titanium nitride layer32 was formed in thickness of 100 nm by a sputtering method.Subsequently, a silicon oxide layer 33 was formed in thickness of 200 nmby a sputtering method. The film formation conditions of the siliconoxide layer 33 were made as 150° C. of the substrate temperature, 0.4 Paof the film forming pressure, 3 kW of the film forming electric power,Argon volumetric flow rate/oxygen volumetric flow rate=35 sccm/15 sccmby utilizing a sputtering apparatus of RF method, and by utilizingsilicon oxide target (diameter, 30.5 cm).

Subsequently, a primary coat insulating layer was formed on the siliconoxide layer 33 by a plasma CVD method. As a primary coat insulatinglayer, a silicon oxynitride film 34 a (composition ratio Si=32%, O=27%,N=24%, and H=17%) prepared from the raw material gases SiH₄, NH₃, andN₂O was formed in thickness of 50 nm at 300° C. of the film formationtemperature by a plasma CVD method. Subsequently, after the surface waswashed by ozone water, the oxide film of the surface was removed bydilute hydrofluoric acid (1:100 dilution). Subsequently, a siliconoxynitride film 34 b (composition ratio Si=32%, O=59%, N=7%, and H=2%)prepared from the raw material gases SiH₄ and N₂O was lamination-formedin thickness of 100 nm at 300° C. of the film formation temperature by aplasma CVD method, and further, a semiconductor layer (here, anamorphous silicon layer 35) having an amorphous structure was formed inthickness of 54 nm at 300° C. of the film formation temperature withoutthe air release by a plasma CVD method (FIG. 3 A).

Subsequently, nickel acetate solution containing 10 ppm of nickel whenit is converted to weight was coated by a spinner. A method of spreadingover the entire surface with nickel element by a sputtering methodinstead of coating may be employed. Subsequently, a semiconductor filmhaving a crystal structure (here, polysilicon layer 36) was formed byperforming the heat processing and crystallizing it (FIG. 3B). Here,after the heat processing (500° C., one hour) for dehydrogenation wascarried out, a silicon film having a crystal structure was obtained byperforming the heat processing for crystallization (550° C., 4 hours).It should be noted that although here, a crystallization technologyusing nickel as a metal element for promoting the crystallization ofsilicon is used, the other known crystallization technology, forexample, solid phase crystallization method or laser crystallizationmethod may be used. Subsequently, as an adhesive layer 37, an epoxyresin was used, and a film substrate 38 (here, polyethyleneterephthalate (PET)) was pasted on a polysilicon layer (FIG. 3C).

After the state of FIG. 3 C was obtained, these were pulled by humanhands so that the film substrate 38 and the substrate 30 would beseparated. It could be recognized that at least titanium nitride andaluminum-silicon alloy layer remained on the substrate 30 which has beenpulled away. It is expected that it is peeled off on the inside of thesilicon oxide 33 or on the interface with the silicon oxide 33 by thisexperiment.

In this way, the peeled layer can be peeled off from the entire surfaceof the substrate 30 by providing an oxide layer being in contact with anitride layer or a metal layer and pulling away the peeled layerprovided on the relevant oxide layer.

(Experiment 2)

In order to specify the location where the peeling off was occurred, itwas partially peeled off by a method of peeling off of the presentinvention, and an experiment for examining the cross section nearby itsboundary was carried out.

As a substrate, the glass substrate (#1737) was used. Moreover, on thesubstrate, a titanium nitride layer was formed in thickness of 100 nm onthe substrate by a sputtering method.

Subsequently, a silicon oxide layer was formed in thickness of 200 nm bya sputtering method. The conditions for film formation of the siliconoxide layer were made as 150° C. of the substrate temperature, 0.4 Pa ofthe film forming pressure, 3 kW of the film formation electric power,Argon volumetric flow rate/oxygen volumetric flow rate=35 sccm/15 sccmby utilizing a sputtering apparatus of RF method, and by utilizingsilicon oxide target (diameter, 30.5 cm).

Subsequently, a primary coat insulating layer was formed on the siliconoxide layer by a plasma CVD method. As a primary coat insulating layer,a silicon oxynitride film (composition ratio Si=32%, O=27%, N=24% andH=17%) prepared from the raw material gases SiH₄, NH₃, and N₂O wasformed in thickness of 50 nm at 300° C. of the film formationtemperature by a plasma CVD method. Subsequently, after the surface waswashed by ozone water, the oxide film of the surface was removed bydilute hydrofluoric acid (1:100 dilution). Subsequently, a siliconoxynitride film (composition ratio Si=32%, O=59%, N=7% and H=2%)prepared from the raw material gases SiH₄ and N₂O was lamination-formedin thickness of 100 nm at 300° C. of the film formation temperature by aplasma CVD method, and further, a semiconductor layer (here, anamorphous silicon layer) having an amorphous structure was formed inthickness of 54 nm at 300° C. of the film formation temperature withoutthe air release by a plasma CVD method.

Subsequently, nickel acetate solution containing 10 ppm of nickel whenconverting to weight value was coated by a spinner. A method ofspreading over the entire surface with nickel element by a sputteringmethod instead of coating may be employed. Subsequently, a semiconductorfilm having a crystal structure (here, polysilicon layer) was formed byperforming the heat processing and crystallizing it. Here, after theheat processing (500° C., one hour) for dehydrogenation was carried out,a silicon film having a crystal structure was obtained by performing theheat processing for crystallization (550° C., 4 hours).

Subsequently, an adhesive tape was pasted on the portion of thepolysilicon layer, and these were pulled so that the adhesive tape andthe substrate are separated by human hands. Then, only the locationwhere the adhesive tape was pasted was peeled off, and transferred tothe tape. A TEM photograph on the peeled boundary on the substrate sideis shown in FIG. 20 A, and its schematic diagram is shown in FIG. 20 B.

As shown in FIG. 20, the titanium nitride layer entirely remained on theglass substrate, the portion where the tape was adhered and transferredwas clearly transferred, the lamination (SiO₂ film by a sputteringmethod, the insulating films (1) and (2) by PCVD method, and polysiliconfilm) was removed. From these, it is understood that the peelingoccurred on the interface between the titanium nitride layer and SiO₂film by a sputtering method.

(Experiment 3)

Here, in the case where the material of a nitride layer or a metal layerwas made TiN, W and WN, in order to verify whether or not the peeledlayer provided on the oxide layer can be peeled off, the followingexperiment was carried out by providing an oxide layer (silicon oxide:film thickness, 200 nm) being in contact with the nitride layer or themetal layer.

As the Sample 1, after TiN was formed in film thickness of 100 nm on theglass substrate by utilizing a sputtering method, a silicon oxide filmwith a thickness of 200 nm was formed by sputtering. After performingthe step of the formation of the silicon oxide, the lamination andcrystallization were performed similarly to Experiment 1.

As a Sample 2, after W was formed in film thickness of 50 nm on theglass substrate by a sputtering method, a silicon oxide film of 200 nmin thickness was formed by utilizing a sputtering method. Afterperforming the step of the formation of the silicon oxide film, thelamination and crystallization were performed similarly to Experiment 1.

As a Sample 3, after WN was formed in film thickness of 50 nm on theglass substrate by a sputtering method, a silicon oxide film of 200 nmin thickness was formed by utilizing a sputtering method. Afterperforming the step of the formation of the silicon oxide film, thelamination and crystallization were performed similarly to Experiment 1.

In this way, Samples 1-3 were formed, and in order to confirm whether ornot the peeled layer is peeled off by adhering an adhesive tape to thepeeled layer, an experiment was carried out. The results are shown inTable 1.

TABLE 1 First material Second material layer layer (Lower layer) (Upperlayer) Tape test Sample 1 TiN (100 nm) Silicon oxide Peeled off (200 nm)Sample 2 W (50 nm) Silicon oxide Peeled off (200 nm) Sample 3 WN (50 nm)Silicon oxide Peeled off (200 nm)

Moreover, the internal stress on the respective silicon oxide film, TiNfilm, W film before and after the heat processing (550° C., 4 hours) wasmeasured. The results are indicated in Table 2.

TABLE 2 Internal stress value of film (dyne/cm²) After film formationAfter heat processing Silicon oxide −9.40E+08 −1.34E+09  film −9.47E+08−1.26E+09  TiN film  3.90E+09 4.36E+09  3.95E+09 4.50E+09 W film−7.53E+09 8.96E+09 −7.40E+09 7.95E+09

It should be noted that as for the silicon oxide film, the film formedin film thickness of 400 nm on the silicon substrate by a sputteringmethod was measured. As for TiN film and W film, after these were formedin film thickness of 400 nm on the glass substrate by a sputteringmethod, the internal stress was measured, then, an silicon oxide filmwas laminated as a cap film. After the heat processing was performed,the cap film was removed by an etching, and then the internal stress wasmeasured again. Moreover, 2 pieces of the respective sample was preparedand the measurements were carried out.

As for W film, although it has the compressive stress (about −7×10⁹(Dyne/cm²)) immediately after the film formation, the film has thetensile stress (about 8×10⁹-9×10⁹ (Dyne/cm²)) by the heat processing,and the peeling off state was excellent. As for TiN film, the stress washardly changed before and after the heating processing, it remained asit had the tensile stress (about 3.9×10⁹-4.5×10⁹ (Dyne/cm²)). Moreover,as for the silicon oxide film, the stress was hardly changed before andafter the heat processing, it remained as it had the compressive stress(about −9.4×10⁸-−1.3×10⁹ (Dyne/cm²)).

From these results, it can be read that the peeling phenomenon relatesto adhesiveness due to a variety of factors, however, particularly, isdeeply concerned with the internal stress, in the case where the oxidelayer was formed on the nitride layer or the metal layer, the peeledlayer can be peeled off from the entire surface of the interface betweenthe nitride layer or the metal layer and the oxide layer.

(Experiment 4)

To examine dependency on a heating temperature, the following experimentwas conducted.

As a sample, after forming a W film (tungsten film) over a substrate toa thickness of 50 nm by sputtering, a silicon oxide film was formed to athickness of 200 nm by using a sputtering (argon gas flow rate of 10sccm, oxygen gas flow rate of 30 sccm, a film formation pressure of 0.4Pa, sputtering electric power of 3 kW, a substrate temperature of 300°C., using a silicon target). Next, a primary coat insulating layer(silicon oxinitride film of 50 nm and silicon oxinitride film of 100 nm)and an amorphous silicon film of 54 nm in thickness are formed by plasmaCVD in the same way as Experiment 1.

Next, after conducting heat treatment while varying conditions ofheating temperatures, a quartz substrate is stuck on an amorphoussilicon film (or a polysilicon film) by using an adhesive material, andthe quartz substrate and the glass substrate are separated from eachother by pulling them away by human's eye to examine whether they can bepeeled off or not. The condition 1 for the heating temperature is 500°C. and 1 hour, and the condition 2 is 450° C. and 1 hour, and thecondition 3 is 425° C. and 1 hour, the condition 4 is 410° C. and 1hour, and the condition 5 is 400° C. and 1 hour, and the condition 6 is350° C. and 1 hour.

As a result of the experiments, the sample can be peeled off under theconditions 1 to 4. The sample can not be peeled off under the conditions5 and 6. Accordingly, in the peeling off method according to the presentinvention, it is preferred that the thermal treatment is conducted atleast 410° C. or higher.

Further, when the W film is peeled off, the W film remains on the entiresurface of the glass substrate, and a lamination layer (SiO₂ film bysputtering, and insulating films (1) and (2) by PCVD, and an amorphoussilicon film) is transferred on the quarts substrate. FIG. 21 showsresults for measuring a surface of the transferred SiO₂ film by TXRF.The surface roughness Rz (thirty points) are 5.44 nm by AFM measurement.Further, FIG. 22 shows results for measuring a surface of the W filmwith 50 nm formed on the quartz substrate as a reference. The surfaceroughness Rz (thirty points) is 22.8 nm by AFM measurement. Further,FIG. 23 shows results for measuring only the quartz substrate by TXRF.Because W (tungsten) peaks of FIGS. 21 and 22 are similar when they arecompared, it is found that a little metallic material (tungsten here) isstuck on a surface of the transferred SIO₂ film.

According to constitution of the present invention disclosed in thepresent specification, a semiconductor device comprises a support, and apeeled off layer adhered to the support by an adhesive material, and asilicon oxide film, a little metallic material provided between thesilicon oxide film and the adhesive material.

In the above constitution, the metallic material comprises an elementselected from the group consisting of W, Ti, Al, Ta, Mo, Cu, Cr, Nd, Fe,Ni, Co, Zr, Zn, Ru, Rh, Pd, Os, Ir and Pt, or an alloy material or acompound material which comprises the above element as a main component.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to 1C are diagrams for illustrating Embodiment 1 of the presentinvention;

FIGS. 2A to 2 c are diagrams for illustrating Embodiment 2 of thepresent invention;

FIGS. 3A to 3D are diagrams for illustrating experiments of the presentinvention;

FIGS. 4A to 4C are diagrams for illustrating Embodiment 3 of the presentinvention;

FIGS. 5A to 5C are diagrams for illustrating Embodiment 4 of the presentinvention;

FIGS. 6A to 6D are diagrams showing the preparing steps of active matrixsubstrate;

FIGS. 7A to 7C are diagrams showing the preparing steps of active matrixsubstrate;

FIG. 8 is a diagram showing an active matrix substrate;

FIGS. 9A to 9D are diagrams for illustrating Example 2 of the presentinvention;

FIGS. 10A to 10E are diagrams for illustrating Example 3 of the presentinvention;

FIG. 11 is a diagram for illustrating Example 4 of the presentinvention;

FIG. 12 is a diagram for illustrating Example 5 of the presentinvention;

FIGS. 13A to 13D are diagrams for illustrating Example 6 of the presentinvention;

FIGS. 14A to 14C are diagrams for illustrating Example 7 of the presentinvention;

FIG. 15 is a diagram for illustrating Example 8 of the presentinvention;

FIGS. 16A and 16B are diagrams for illustrating Example 9 of the presentinvention;

FIG. 17 is a diagram for illustrating Example 9 of the presentinvention;

FIGS. 18A to 18F are diagrams showing one example of an electronicequipment;

FIGS. 19A to 19C are diagrams showing one example of an electronicequipment;

FIGS. 20A and 20B are cross sectional TEM photograph and a schematicdiagram of the boundary location partially peeled off.

FIG. 21 is a graph showing results for measuring a surface of the peeledoff silicon oxide film by TXRF.

FIG. 22 is a graph showing results for measuring a surface of W filmformed on a quartz substrate by TXRF. (Reference)

FIG. 23 is a graph showing results for measuring a surface of a quartzsubstrate by TXRF. (Reference)

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, embodiments of the present invention will be described.

Embodiment 1

Hereinafter, a representative peeling off procedure utilizing thepresent invention will be schematically shown with reference to FIG. 1.

In FIG. 1 A, the reference numeral 10 denotes a substrate, the referencenumeral 11 denotes a nitride layer or a metal layer, the referencenumeral 12 denotes an oxide layer, and the reference numeral 13 denotesa peeled off layer.

In FIG. 1 A, as for the substrate 10, a glass substrate, a quartzsubstrate, a ceramic substrate or the like can be used. Moreover, asilicon substrate, a metal substrate or a stainless substrate may alsobe used.

First, as shown in FIG. 1 A, the nitride layer or metal layer 11 isformed on the substrate 10. As the nitride layer or metal layer 11,representative examples are as follows: an element selected from Ti, Al,Ta, W, Mo, Cu, Cr, Nd, Fe, Ni, Co, Zr, Zn, Ru, Rh, Pd, Os, Ir and Pt, ora monolayer consisted of alloy materials or compound materials whoseprincipal components are the foregoing elements or a lamination ofthese, or a monolayer consisted of these nitrides, for example, titaniumnitride, tungsten nitride, tantalum nitride, molybdenum or a laminationof these. These may be used. Subsequently, the oxide layer 12 is formedon the nitride layer or metal layer 11. As the oxide layer 12, onerepresentative example may use silicon oxide, oxynitride silicon andmetal oxide materials. As for the oxide layer 12, film formation methodssuch as sputtering method, plasma CVD method, coating method may beused. In the present invention, it is important that the film stress ofthis oxide layer 12 and the film stress of the nitride layer or metallayer 11 are made different from each other. The respective filmthickness is appropriately set in the range from 1 nm to 1000 nm, andthe respective film stress may be adjusted. Moreover, FIG. 1, in orderto contemplate the simplification of the process, one example in whichthe nitride layer or metal layer 11 being in contact with the substrate10 is formed has been shown, but the adhesiveness with the substrate 10may be enhanced by providing an insulating layer or metal layer betweenthe substrate 10 and the nitride layer or metal layer 11.

Subsequently, a peeled off layer 13 is formed on the oxide layer 12(FIG. 1A). The peeled off layer may be a layer containing a variety ofelements (thin film diode, photoelectric conversion element comprisingPIN junction of silicon, and silicon resistance element) whoserepresentative is TFT. Moreover, the heat processing in the range wherethe substrate 10 is endurable can be performed. It should be noted thatin the present invention, even if the film stress of the oxide layer 12and the film stress of the nitride layer or metal layer 11 aredifferent, the film peeling or the like does not occur by the heatprocessing in the preparing step of the peeled off layer 13.

Subsequently, the substrate 10 on which the nitride layer or metal layer11 is provided is pulled away by the physical means (FIG. 1B). Since thefilm stress of the oxide layer 12 and the film stress of the nitridelayer or metal layer 11 are different, these can be pulled away by acomparatively small force. Moreover, although here, one example in whichit is supposed that the peeled off layer 13 has a sufficient mechanicalstrength is shown, in the case where the mechanical strength of thepeeled off layer 13 is not sufficient, it is preferred that after thesupporting body (not shown) for fixing the peeled off layer 13 waspasted, it is peeled off. In this way, the peeled off layer 13 formed onthe oxide layer 12 can be separated from the substrate 10. The stateafter it was peeled off is shown in FIG. 1 C. In Experiment, in the casewhere tungsten film has thickness of 10 nm as the metal layer 11, andthe silicon oxide film has thickness of 200 nm as an oxide layer 12 by asputtering method, the peeling off could be confirmed according to apeeling off method of the present invention. In the case where tungstenfilm has thickness of 50 nm as the metal layer 11, and the silicon oxidefilm has thickness of 100 nm as an oxide layer 12 by a sputteringmethod, the peeling off could be confirmed according to a peeling offmethod of the present invention. In the case where tungsten film hasthickness of 50 nm as the metal layer 11, and the silicon oxide film hasthickness of 400 nm as an oxide layer 12 by sputtering method, thepeeling off could be confirmed according to a peeling off method of thepresent invention. Moreover, after it was peeled off, the peeled offlayer 13 pulled away may be pasted on the transferring body (not shown).

Moreover, the present invention can be applied to a method of preparinga variety of semiconductor devices. Particularly, it can be made lightby using plastic substrate for a transferring body and supporting body.In the case where a liquid crystal display device is prepared, thesupporting body is made as an opposing substrate, the supporting bodymay be adhered to the peeled layer by utilizing a seal member as anadhesive member. In this case, an element provided on the foregoingpeeled layer has a pixel electrode, and it is made so that a liquidcrystal material is packed between the relevant pixel electrode and theforegoing opposing substrate. Moreover, the order of the processes forthe preparation of a liquid crystal display device is not particularlylimited, and an opposing substrate as a supporting body was pasted.After the liquid crystal was implanted, the substrate may be peeled offand pasted on a plastic substrate as a transferring body, or after thepixel electrode was formed, the substrate may be peeled off, after theplastic substrate as the first transferring body was pasted, theopposing substrate as the second transferring body may be pasted.

Moreover, in the case where a light emitting device represented by alight emitting device having an OLED is prepared, it is preferable thatthe supporting body is made as a sealing medium, a light emittingelement is completely interrupted from the exterior so as to preventsubstances such as water content, oxygen or the like which promotes thedeterioration of an organic compound layer from penetrating from theexterior. Moreover, in the case where a light emitting devicerepresented by a light emitting device having an OLED is prepared, it ispreferable that substances such as water, oxygen or the like promotingthe deterioration of the organic compound layer is sufficientlyprevented from penetrating from the exterior not only into thesupporting body but also the transferring body. Moreover, the order ofthe processes for the preparation of alight emitting device is notparticularly limited.

After a light emitting element was formed, a plastic substrate as asupporting body may be pasted, the substrate may be peeled off, and theplastic substrate as a transferring body may be pasted, or after a lightemitting element was formed, the substrate may be peeled off, and afterthe plastic substrate as the first transferring body was pasted, theplastic substrate as the second transferring body may be pasted.

Embodiment 2

As for the present Embodiment, the peeling off procedure for peeling offthe substrate while the impurities diffusion from the nitride layer ormetal layer and the substrate is prevented by providing a primary coatinsulating layer being in contact with the peeled off layer isschematically shown in FIG. 2. In FIG. 2 A, the reference numeral 20denotes a substrate, the reference numeral 21 denotes a nitride layer ora metal layer, the reference numeral 22 denotes an oxide layer, thereference numerals and characters 23 a and 23 b denote primary coatinsulating layers, and the reference numeral 24 denotes a peeled offlayer. In FIG. 2 A, as for the substrate 20, a glass substrate, a quartzsubstrate, a ceramic substrate or the like can be used. Moreover, asilicon substrate, a metal substrate or a stainless substrate may alsobe used.

First, as shown in FIG. 2 A, the nitride layer or metal layer 21 isformed on the substrate 20. As the nitride layer or metal layer 21,representative examples are as follows: an element selected from Ti, Al,Ta, W, Mo, Cu, Cr, Nd, Fe, Ni, Co, Zr, Zn, Ru, Rh, Pd, Os, Ir and Pt, ora monolayer consisted of alloy materials or compound materials whoseprincipal components are the foregoing elements or a lamination ofthese, a monolayer consisted of these nitrides, for example, titaniumnitride, tungsten nitride, tantalum nitride, molybdenum nitride or alamination of these. These may be used. Subsequently, the oxide layer 22is formed on the nitride layer or metal layer 21. As the oxide layer 22,one representative example may use silicon oxide, oxynitride silicon,and metal oxide materials. It should be noted that any film formationmethod such as a sputtering method, a plasma CVD method, coating methodor the like might be applied to the oxide layer 22.

In the present invention, it is important that the film stress of thisoxide layer 22 and the film stress of the nitride layer or metal layer21 are made different. The respective film thickness is appropriatelyset in the range from 1 nm to 1000 nm, and the respective film stressmay be adjusted. Moreover, FIG. 2, in order to contemplate thesimplification of the process, one example in which the nitride layer ormetal layer 21 being in contact with the substrate 20 is formed has beenshown, but the adhesiveness with the substrate 20 may be enhanced byproviding an insulating layer or metal layer between the substrate 20and the nitride layer or metal layer 21.

Subsequently, a primary coat insulating layers 23 a and 23 b were formedon the oxide layer 22 by plasma CVD method. Here, the silicon oxynitridefilm 23 a (composition ratio Si=32%, O=27%, N=24% and H=17%) preparedfrom the raw material gases SiH₄, NH₃, and N₂O was formed (preferably,10-200 nm) in thickness of 50 nm at 400° C. of the film formationtemperature by a plasma CVD method, and further the silicon oxynitridefilm 23 b (composition ratio Si=32%, O=59%, N=7% and H=2%) prepared fromthe raw material gases SiH₄ and N₂O was lamination-formed (preferably,50-200 nm) in thickness of 100 nm at 400° C. of the film formationtemperature by a plasma CVD method. But it is not particularly limited,and a monolayer or a lamination having three layers or more may be used.Subsequently, a peeled off layer 24 is formed on the primary coatinsulating layer 23 b (FIG. 2 A). In this way, in the case wheretwo-layer primary coat insulating layers 23 a and 23 b were made, in theprocess in which the peeled off layer 24 is formed, diffusion of theimpurities from the nitride layer or the metal layer 21 and thesubstrate 20 can be prevented. Moreover, the adhesiveness between theoxide layer 22 and the peeled off 24 can be enhanced by utilizing theprimary coat insulating layers 23 a and 23 b.

Moreover, in the case where the concave and convex are formed on thesurface due to the nitride layer or metal layer 21 and the oxide layer22, the surface may be flattened before and after the primary coatinsulating layer is formed. The coverage on the peeled off layer 24becomes more excellent when it is flattened, in the case where thepeeled off layer 24 containing an element 24 is formed, it is preferablesince the element characteristics become easily stable. It should benoted that as a flattening processing, an etch back method in which anetching or the like is performed after the formation of the coated film(resist film or the like), a chemical mechanical polishing method (CMPmethod) or the like may be used.

Subsequently, the substrate 20 on which the nitride layer or metal layer21 is provided is pulled away by the physical means (FIG. 2 B). Sincethe film stress of the oxide layer 22 and the film stress of the nitridelayer or metal layer 21 are different, these can be pulled away by acomparatively small force. Moreover, although here, one example in whichit has been supposed that the peeled off layer 24 has a sufficientmechanical strength is shown, in the case where the mechanical strengthof the peeled off layer 24 is not sufficient, it is preferred that afterthe supporting body (not shown) for fixing the peeled off layer 24 waspasted, it is peeled off.

In this way, the peeled off layer 24 formed on the primary coatinsulating layer 22 can be separated from the substrate 20. The stateafter it was peeled off is shown in FIG. 2 C.

Moreover, after it was peeled off, the peeled off layer 24 pulled awaymay be pasted on the transferring body (not shown).

Moreover, the present invention can be applied to a method of preparinga variety of semiconductor devices. Particularly, it can be made lightby using plastic substrate for a transferring body and supporting body.In the case where a liquid crystal display device is prepared, thesupporting body is made as an opposing substrate, the supporting bodymay be adhered to the peeled layer by utilizing an sealing medium as anadhesive member. In this case, an element provided on the peeled layerhas a pixel electrode, and it is made so that a liquid crystal materialis packed between the relevant pixel electrode and the foregoingopposing substrate. Moreover, the order of the processes for theproduction of a liquid crystal display device is not particularlylimited, an opposing substrate as a supporting body was pasted, afterthe liquid crystal was implanted, and the substrate may be peeled offand pasted on a plastic substrate as a transferring body, or after thepixel electrode was formed, the substrate may be peeled off. After theplastic substrate as the first transferring body was pasted, theopposing substrate as the second transferring body may be pasted.

Moreover, in the case where a light-emitting device represented by alight emitting device having an OLED is prepared, it is preferable thatthe supporting body is made as a sealing medium, a light emittingelement is completely interrupted from the exterior so as to preventsubstances such as water content, oxygen or the like which promotes thedeterioration of an organic compound layer from penetrating from theexterior. Moreover, in the case where a light-emitting devicerepresented by a light emitting device having an OLED is prepared, it ispreferable that substances such as water content, oxygen or the likepromoting the deterioration of the organic compound layer issufficiently prevented from penetrating from the exterior not only intothe supporting body but also the transferring body. Moreover, the orderof the processes for the preparation of a light emitting device is notparticularly limited, after a light emitting element was formed, aplastic substrate as a supporting body may be pasted, the substrate maybe peeled off, and the plastic substrate as a transferring body may bepasted, or after a light emitting element was formed, the substrate maybe peeled off, and after the plastic substrate as the first transferringbody was pasted, the plastic substrate as the second transferring bodymay be pasted.

Embodiment 3

In the present embodiment, in addition to Embodiment 1, an example inwhich the irradiation of laser beam or the heat processing is performedin order to promote the peeling off is shown in FIG. 4.

In FIG. 4 A, the reference numeral 40 denotes a substrate, the referencenumeral 41 denotes a nitride layer or a metal layer, the referencenumeral 42 denotes an oxide layer and the reference numeral 43 denotes apeeled off layer.

Since the step of forming it until the peeled off layer 43 is made isthe same with Embodiment 1, the description is omitted.

After the peeled off layer 43 was formed, the irradiation of laser beamis performed (FIG. 3 A). As a laser beam, a gas laser such as an excimerlaser or the like, a solid state laser such as YVO₄ laser, YAG laser orthe like, and a semiconductor laser may be used. Moreover, the form oflaser may be either of continuous oscillation or pulse oscillation, andthe shape of the laser beam may be any of linear, rectangular, circular,or elliptical shape. Moreover, the wavelength to be used may be any offundamental wave, the second higher harmonic wave, or the third higherharmonic wave.

Moreover, it is desirable that a material used for the nitride layer ormetal layer 41 is a material easily absorbing the laser beam, andtitanium nitride is preferred. It should be noted that in order to makethe laser beam pass, a substrate having a transparency is used for thesubstrate 40.

Subsequently, the substrate 40 on which the nitride layer or metal layer41 is provided is pulled away by the physical means (FIG. 4 B). Sincethe film stress of the oxide layer 42 and the film stress of the nitridelayer or metal layer 41 are different, these can be pulled away by acomparatively small force.

The film stresses can be changed each other and the peeling can bepromoted by irradiating the laser beam and heating the interface betweenthe nitride layer or metal layer 41 and the oxide layer 42, and thepeeling off can be performed by smaller force. Moreover, although here,one example in which it is supposed that the peeled off layer 43 has asufficient mechanical strength is shown, in the case where themechanical strength of the peeled off layer 43 is not sufficient, it ispreferred that after the supporting body (not shown) for fixing thepeeled off layer 43 was pasted, it is peeled off.

In this way, the peeled off layer 43 formed on the oxide layer 42 can beseparated from the substrate 40. The state after it was peeled off isshown in FIG. 4 C. Moreover, it is not limited to the laser beam, avisible light from the light source such as a halogen lump or the like,an infrared ray, an ultraviolet ray, a microwave or the like may beused.

Moreover, instead of laser beam, the heat processing in an electricfurnace may be available.

Moreover, before the supporting body is adhered, or before it is peeledoff by the foregoing physical means, the heating processing or theirradiation of laser beam may be performed.

Furthermore, the present Embodiment can be combined with Embodiment 2.

Embodiment 4

In the present embodiment, in addition to Embodiment 1, an example inwhich an oxide in a granular shape is provided on the interface betweenthe nitride layer or metal layer and the oxide layer in order to promotethe peeling off is shown in FIG. 5.

In FIG. 5 A, the reference numeral 50 denotes a substrate, the referencenumeral 51 denotes a nitride layer or a metal layer, the referencenumeral 52 a denotes an oxide layer in a granular shape, the referencenumeral 52 b denotes an oxide layer, and the reference numeral 53denotes a peeled off layer.

Since the step of forming it until the nitride layer or metal layer 51is formed is the same with Embodiment 1, the description is omitted.

After the nitride layer or metal layer 51 was formed, the oxide in agranular shape 52 a is formed. As the oxide in a granular shape 52 a, ametal oxide material, form example, ITO (indium oxide-tin oxide alloy),indium oxide-zinc oxide alloy (In₂O₃—ZnO), zinc oxide (ZnO) or the likemay be used.

Subsequently, the oxide layer 52 b for covering the oxide layer 52 a ina granular shape is formed. As the oxide layer 52 b, one representativeexample may use silicon oxide, oxynitride silicon, and metal oxidematerials. It should be noted that any film formation method such as asputtering method, a plasma CVD method, coating method or the like mightbe applied to the oxide layer 23 b.

Subsequently, a peeled off layer 53 is formed on the oxide layer 52 b(FIG. 5 A).

Subsequently, the substrate 50 on which the nitride layer or metal layer51 is provided is pulled away by the physical means (FIG. 5 B). Sincethe film stress of the oxide layer 52 and the film stress of the nitridelayer or metal layer 51 are different, these can be pulled away by acomparatively small force.

The bonding force between the nitride layer or metal layer 51 and theoxide layer 52 is weakened, the adhesiveness from each other is changed,the peeling off can be promoted by providing the oxide in a granularshape 52 b and these can be peeled off by smaller force. Moreover,although here, an example in which it is supposed that the peeled offlayer 53 has a sufficient mechanical strength is shown, in the casewhere the mechanical strength of the peeled off layer 53 is notsufficient, it is preferred that after the supporting body (not shown)for fixing the peeled off layer 53 was pasted, it is peeled off.

In this way, the peeled off layer 53 formed on the oxide layer 52 b canbe separated from the substrate 50. The state after it was peeled off isshown in FIG. 5 C. Furthermore, the present Embodiment can be combinedwith Embodiment 2 or Embodiment 3.

The present invention comprising the above-described constitutions willbe described in detail with reference to Examples shown below.

EXAMPLES Example 1

Examples of the present invention will be described with reference toFIG. 6 through FIG. 8. Here, a method in which a pixel section and TFTof a drive circuit provided on the periphery of the pixel section(n-channel type TFT and p-channel type TFT) are prepared at the sametime on the same substrate will be described in detail.

First, the nitride layer or metal layer 101, the oxide layer 102 and theprimary coat insulating film 103 are formed on the substrate 100, aftera semiconductor film having a crystal structure was obtained, asemiconductor layers 104-108 isolated in a island shape are formed byetching processing in the desired shape.

As the substrate 100, the glass substrate (#1737) is used.

Moreover, as the metal layer 101, an element selected from Ti, Al, Ta,W, Mo, Cu, Cr, Nd, Fe, Ni, Co, Zr, Zn, Ru, Rh, Pd, Os, Ir and Pt, or amonolayer consisted of alloy materials or compound materials whoseprincipal components are the foregoing elements or a lamination of thesemay be used. More preferably, a monolayer consisted of these nitrides,for example, titanium nitride, tungsten nitride, tantalum nitride,molybdenum nitride or a lamination of these may be used. Here, titaniumnitride film having film thickness of 100 nm is utilized by a sputteringmethod.

Moreover, as the oxide layer 102, a monolayer consisted of a siliconoxide material or a metal oxide material, or a lamination of these maybe used. Here, a silicon oxide film having film thickness of 200 nm isused by a sputtering method. The bonding force between the metal layer101 and the oxide layer 102 is strong in heat processing, the filmpeeling (also referred to as solely “peeling”) or the like does notoccur. However, it can be easily peeled off on the inside of the oxidelayer or on the interface by the physical means.

Subsequently, as a primary coat insulating layer, a silicon oxynitridefilm 103 a (composition ratio Si=32%, O=27%, N=24% and H=17%) preparedfrom the raw material gases SiH₄, NH₃, and N₂O was formed (preferably,10-200 nm) in thickness of 50 nm at 400° C. of the film formationtemperature by a plasma CVD method. Subsequently, after the surface waswashed by ozone water, the oxide film of the surface was removed bydilute hydrofluoric acid (1:100 dilution). Subsequently, a siliconoxynitride film 103 b (composition ratio Si=32%, O=59%, N=7% and H=2%)prepared from the raw material gases. SiH₄ and N₂O was lamination-formed(preferably, 50-200 nm) in thickness of 100 nm at 400° C. of the filmformation temperature by a plasma CVD method, and further, asemiconductor layer (here, an amorphous silicon layer) having anamorphous structure was formed (preferably, 25-80 nm) in thickness of 54nm at 300° C. of the film formation temperature without the air releaseby a plasma CVD method.

In the present Example, although the primary coat film 103 is shown as atwo-layer structure, a monolayer film of the foregoing insulating filmor a layer as a structure in which two layers or more are laminated maybe formed. Moreover, there are no limitations to materials for asemiconductor film, but preferably, it may be formed using a silicon ora silicon germanium (Si_(x)Ge_(1-x) (X=0.0001-0.02)) alloy or the likeby the known means (sputtering method, LPCVD method, plasma CVD methodor the like). Moreover, a plasma CVD apparatus may be sheet typeapparatus, or batch type apparatus. Moreover, the primary insulatingfilm and the semiconductor film may be continuously formed in the samefilm formation chamber without contacting with the air.

Subsequently, after the surface of the semiconductor film having anamorphous structure was washed, an oxide film having an extremely thinthickness of about 2 nm is formed on the surface with ozone water.Subsequently, in order to control the threshold value of TFT, a dopingof a trace of impurity element (boron or phosphorus) is performed. Here,boron was added to the amorphous silicon film under the dopingconditions of 15 kV of acceleration voltage, 30 sccm of flow rate of thegas in which diborane was diluted into 1% with hydrogen, 2×10¹²/cm² ofdosage without mass segregating diborane (B₂H₆) by utilizing an iondoping method in which plasma excitation was performed.

Subsequently, nickel acetate solution containing 10 ppm of nickel whenit is converted to weight was coated by a spinner. A method of spreadingover the entire surface with nickel element by a sputtering methodinstead of coating may be employed.

Subsequently, a semiconductor film having a crystal structure was formedby performing the heat processing and crystallizing it. For this heatprocessing, the heat processing of an electric furnace or theirradiation of strong light may be used. In the case where it isperformed by utilizing the heat processing of the electric furnace, itmay be performed at 500° C.-650° C. for 4-24 hours. Here, after the heatprocessing (500° C., one hour) for dehydrogenation was carried out, asilicon film having a crystal structure was obtained by performing theheat processing for crystallization (550° C., 4 hours). It should benoted that although here, crystallization was performed using the heatprocessing by the furnace, however, the crystallization may be performedby a lamp anneal apparatus.

It should be noted that here, a crystallization technology using nickelas a metal element for promoting the crystallization of silicon is used.However, the other known crystallization technology, for example, solidphase crystallization method or laser crystallization method may beused.

Subsequently, after the oxide film of the surface of the silicon filmhaving a crystal structure was removed by dilute hydrofluoric acid orthe like, the irradiation of the first laser beam (XeCl: wavelength 308nm) for enhancing the crystallization ratio and repairing the defaultsremained within the crystal grain is performed in the air, or in theoxygen atmosphere. For a laser beam, an excimer laser beam of 400 nm orless of wavelength, the second higher harmonic wave, the third higherharmonic wave of YAG laser are used. Anyhow, using pulse laser beamhaving about 10-1000 Hz of repeated frequency, the relevant laser beamis condensed at 100-500 mJ/cm² by an optical system, irradiated withoverlap ratio of 90-95% and it may be made it scan the surface of thesilicon film. Here, the irradiation of the first laser beam is performedat repeated frequency of 30 Hz, 393 mJ/cm² of energy density in the air.It should be noted that since it is performed in the air, or in theoxygen atmosphere, an oxide film is formed on the surface by theirradiation of the first laser beam.

Subsequently, after the oxide film formed by irradiation of the firstlaser beam was removed by dilute hydrofluoric acid, the irradiation ofthe second laser beam is performed in the nitrogen atmosphere or in thevacuum, thereby flattening the surface of the semiconductor film. Forthis laser beam (second laser beam), an excimer laser beam having awavelength of 400 nm or less, the second higher harmonic wave, the thirdhigher harmonic wave of YAG laser are used. The energy density of thesecond laser beam is made larger than the energy density of the firstlaser beam, preferably, made larger by 30-60 mJ/cm². Here, theirradiation of the second laser beam is performed at 30 Hz of therepeated frequency and 453 mJ/cm² of energy density, P-V value (Peak toValley, difference between the maximum value and minimum value) of theconcave and convex in the surface of the semiconductor film is to be 50nm or less. This P-V value is obtained by an AFM (atomic forcemicroscope). Moreover, in the present Example, the irradiation of thesecond laser beam was performed on the entire surface. However, sincethe reduction of the OFF-state current is particularly effective to theTFT of the pixel section, it may be made a step of selectivelyirradiating only on at least pixel section.

Subsequently, a barrier layer consisted of an oxide film of total 1-5 nmin thickness is formed by processing the surface with ozone water for120 seconds.

Subsequently, an amorphous silicon film containing argon element whichis to be gettering site is formed in film thickness of 150 nm on thebarrier layer by a sputtering method. The film formation conditions by asputtering method of the present Example are made as 0.3 Pa of filmformation pressure, 50 (scorn) of gas (Ar) volumetric flow rate, 3 kW offilm formation power, and 150° C. of the substrate temperature. Itshould be noted that the atomic percentage of argon element contained inthe amorphous silicon film under the above-described conditions is inthe range from 3×10²⁰/cm³ to 6×10²⁰/cm³, the atomic percentage of oxygenis in the range from 1×10¹⁹/cm³ to 3×10¹⁹/cm³. Then, the gettering isperformed by carrying out the heat processing at 650° C. for 3 minutesusing a lamp anneal apparatus.

Subsequently, after the barrier layer is made an etching stopper, theamorphous silicon film containing argon element which is the getteringsite was selectively removed, the barrier layer is selectively removedwith dilute hydrofluoric acid. It should be noted that since whengettering, nickel tends to easily move into the higher oxygen densityregion, it is desirable that the barrier layer consisted of an oxidefilm is removed after the gettering.

Subsequently, after a thin oxide film is formed with the ozone water onthe surface of the silicon film (also referred to as “polysilicon film”)having the obtained crystal structure, a mask consisted of a resist isformed, and the semiconductor layers 104-108 isolated in an island shapeis formed in the desired shape by etching processing. After thesemiconductor layer was formed, the mask consisted of the resist isremoved.

Subsequently, the oxide film was removed by an etchant containinghydrofluoric acid, and at the same time, the surface of the silicon filmwas washed, an insulating film whose principal component is silicon andwhich is to be a gate insulating film 109 is formed. In the presentExample, a silicon oxynitride film (composition ratio Si=32%, O=59%,N=7% and H=2%) is formed in thickness of 115 nm by plasma CVD method.

Subsequently, as shown in FIG. 6 A, the first electrically conductivefilm 110 a having film thickness of 20-100 nm and the secondelectrically conductive film 110 b having film thickness of 100-400 nmare lamination-formed on the gate insulating film 109. In the presentExample, a tantalum nitride film having film thickness of 50 nm and atungsten film having film thickness of 370 nm are in turn laminated onthe gate insulating film 109.

As an electrically conductive material for forming the firstelectrically conductive film and the second electrically conductivefilm, it is formed using an element selected from Ta, W, Ti, Mo, Al andCu, or alloy material or compound material whose principal component isthe foregoing element. Moreover, as the first electrically conductivefilm and the second electrically conductive film, a semiconductor filmrepresented by a polycrystal silicon film in which impurity element suchas phosphorus or the like is doped, and Ag, Pd, Cu alloys may be used.Moreover, it is not limited to a two-layer structure. For example, itmay be made a three-layer structure in which a tungsten film having filmthickness of 50 nm, aluminum-silicon (Al—Si) alloy having film thicknessof 500 nm, and a titanium nitride film having film thickness of 30 nmare in turn laminated. Moreover, in the case of a three-layer structure,instead of tungsten of the first electrically conductive film, tungstennitride may be used, instead of aluminum-silicon (Al—Si) alloy of thesecond electrically conductive film, aluminum-titanium (Al—Ti) alloyfilm may be used, or instead of a titanium nitride film of the thirdelectrically conductive film, a titanium film may be used. Moreover, itmay be a monolayer structure.

Next, as shown in FIG. 6B, masks 112-117 consisted of resists are formedby light exposure step, the first etching processing for forming a gateelectrode and wirings is performed. The first etching processing isperformed under the first and second etching conditions. As for anetching, ICP (Inductively Coupled Plasma) etching method may be used.The film can be etched in the desired tapered shape by appropriatelyadjusting the etching conditions (electric energy applied to the coiltype electrode, electric energy applied to the electrode on thesubstrate side, temperature of electrode on the substrate side and thelike). It should be noted that as gas for an etching, chlorine based gaswhich is represented by Cl₂, BCl₃, SiCl₄, CCl₄ or the like, fluorinebased gas which is represented by CF₄, SF₆, NF₃ or the like or O₂ can beappropriately used.

In the present Example, also to the substrate side (sample stage), 150 Wof RF (13.56 MHz) electric power is turned on, substantially negativeself-bias voltage is applied. It should be noted that the size of theelectrode area on the side of the substrate is 12.5 cm×12.5 cm, and thesize of the coil type electrode area (here, quartz disk on which thecoil is provided) is an area of a disk having a diameter of 25 cm. Theend section of the first electrically conductive layer is made in atapered shape by etching W film under the first etching conditions. Theetching rate to W under the first etching conditions is 200.39 nm/min,the etching rate to TaN is 80.32 nm/min, and the selection ratio of W toTaN is about 2.5. Moreover, the tapered angle of W is about 26°. Then,the second etching conditions were changed without removing the masks112-117 consisted of resists, CF₄ and Cl₂ were used for etching gas, therespective ratio of gas volumetric flow rate was made 30/30 (sccm), 500W of RF (13.56 MHz) electric power was turned on to the coil typeelectrode at 1 Pa of the pressure, the plasma was generated and theetching was performed for about 30 seconds. 20 W of RF (13.56 MHz)electric power was also turned on to the side of the electrode (samplestage), and substantially a negative self bias voltage was applied. Theetching rate to W under the second etching conditions was 58.97 nm/min,and the etching rate to TaN was 66.43 nm/min. It should be noted that inorder to etch without remaining residue on the gate insulating film, itmight increase the etching time at the ratio of about 10-20%. In theabove-described first etching processing, the end section of the firstelectrically conductive layer and the second electrically conductivelayer becomes in a tapered shape due to the effect of the bias voltageto be applied to the substrate side by making the mask consisted of aresist adjust to be suitable. The angle of this tapered section may bemade in the range from 15 to 45°.

In this way, electrically conductive layers 119-123 in the first shapeconsisted of the first electrically conductive layer and the secondelectrically conductive layer (first electrically conductive layers 119a-124 a and the second electrically conductive layers 119 b-124 b) areformed by the first etching processing. The insulating film 109 which isto be a gate insulating film is etched about 10-20 nm, becomes a gateinsulating film 118 whose region not covered with the electricallyconductive layers in the first shape 119-123 is made thinner.

Subsequently, the second etching processing is performed withoutremoving the mask consisted of the resist. Here, using SF₆, Cl₂ and O₂for etching gas, the etching was performed for 25 seconds by making theratio of gas volumetric flow rate 24/12/24 (sccm), turning on 700 W ofRF (13.56 MHz) electric power to the coil type electrode and generatingthe plasma at 1.3 Pa of the pressure. 10 W of RF (13.56 MHz) electricpower was also turned on to the side of the electrode (sample stage),and substantially a negative self bias voltage was applied. The etchingrate to W under the second etching conditions was 227.3 nm/min, and theetching rate to TaN was 32.1 nm/min, the selection ratio of W to TaN is7.1, the etching rate to SiON which is an insulating film 118 is 33.7nm/min, and the selection ratio of W to SiON is 6.83. In this way, inthe case where SF₆ is used for etching gas, since the selection ratio tothe insulating film 118 is high, the film reduction can be suppressed.In the present Example, in the insulating film 118, only about 8 nm ofthe film reduction occurred.

The tapered angle became 70° by the second etching processing. Thesecond electrically conductive layers 126 b-131 b are formed by thesecond etching processing. On the other hand, the first electricallyconductive layer is scarcely etched, and becomes the first electricallyconductive layers 126 a-131 a. It should be noted that the sizes of thefirst electrically conductive layers 126 a-131 a are almost the samewith the first electrically conductive layers 119 a-124 a. Actually,although there are some cases where the width of the first electricallyconductive layer is backward by about 0.3 μm comparing to that beforethe second etching, that is, about 0.6 μm in whole line width backward,there is scarcely no change in size.

Moreover, in the case where instead of two-layer structure,three-structure in which a tungsten film having film thickness of 50 nm,an aluminum-silicon (Al—Si) alloy film having film thickness of 500 nm,and a titanium nitride film are in turn laminated is employed, as forthe first etching conditions of the first etching processing, theetching may be performed for 117 seconds by utilizing BCl₃, Cl₂ and O₂as raw material gases, making the respective ratio of gas volumetricflow rates 65/10/5 (sccm), turning on 300 W of RF (13.56 MHz) electricpower to the substrate side (sample stage), turning on 450 W of RF(13.56 MHz) electric power to the coil type electrode at 1.2 Pa of thepressure and generating plasma, as for the second etching conditions ofthe first etching processing, the etching may be performed for about 30seconds by utilizing CF₄, Cl₂ and O₂ as raw material gases, making therespective ratio of gas volumetric flow rates 25/25/10 (sccm), turningon 20 W of RF (13.56 MHz) electric power to the substrate side (samplestage), turning on 500 W of RF (13.56 MHz) electric power to the coiltype electrode at 1 Pa of the pressure and generating a plasma, as forthe second etching processing, the etching may be performed by utilizingBCl₃ and Cl₂ as raw material gases, making the respective ratio of gasvolumetric flow rates 20/60 (sccm), turning on 100 W of RF (13.56 MHz)electric power to the substrate side (sample stage), turning on 600 W ofRF (13.56 MHz) electric power to the coil type electrode at 1.2 Pa ofthe pressure and generating a plasma.

Subsequently, after the mask consisted of the resist was removed, thestate of FIG. 6D is obtained by performing the first doping processing.The doping processing may be carried out by an ion doping method, or ionimplantation method. The conditions of an ion doping method are 1.5×10¹⁴atoms/cm², and 60-100 keV of the acceleration voltage, it is performedunder these conditions. As an impurity element conferring n-type,typically, phosphorus (P) or arsenic (As) are used. In this case, thefirst electrically conductive layers and the second electricallyconductive layers 126-130 are masks with respect to the impurity elementconferring n-type, the first impurity regions 132-136 are formed in aself-aligned manner. The impurity elements conferring n-type are addedin the density range from 1×10¹⁶ to 1×10¹⁷/cm³ to the first impurityregions 132-136. Here, the region having the same density range with thefirst impurity region is also referred to as n−-region.

It should be noted that in the present Example, after the mask consistedof resist was removed, the first doping processing was performed.However, the first doping processing may be performed without removingthe mask consisted of the resist.

Subsequently, as shown in FIG. 7 A, the masks 137-139 consisted ofresists are formed and the second doping processing is performed. Themask 137 is a mask for protecting the channel formation region of thesemiconductor layer forming p-channel type TFT of the drive circuit andits peripheral region, the mask 138 is a mask for protecting the channelformation region of the semiconductor layer forming one of n-channeltype TFT of the drive circuit, and the mask 139 is a mask for protectingthe channel formation region of the semiconductor layer forming TFT ofthe pixel section and its peripheral region, and further a region whichis to be retention volume.

The conditions for ion doping in the second doping processing are1.5×10¹⁵ atoms/cm² of dosage, and 60-100 keV of the accelerationvoltage, and under these conditions, phosphorus (P) is doped. Here, byutilizing the second electrically conductive layers 126 b-128 b asmasks, the impurity region is formed in a self-aligned manner on therespective semiconductor layers. Needless to say, to the region coveredwith the masks 137-139, the impurities are not added. Thus, the secondimpurity regions 140-142 and the third impurity region 144 are formed.The impurity element conferring n-type is added in the density rangefrom 1×10²⁰ to 1×10²¹/cm³ on the second impurity regions 140-142. Here,the region having the same density range with the second impurity regionis also referred to as n+ region.

Moreover, the third impurity region is formed in a lower density thanthat of the second impurity region by the first electrically conductivelayer, the impurity element conferring n-type is added in the densityrange from 1×10¹⁸ to 1×10¹⁹/cm³. It should be noted that as for thethird impurity region, since the doping is performed by making it passthe portion of the first electrically conductive layer and performingthe doping, it has a density gradient in which the impurity densityincreases toward the end section of the tapered section. Here, theregion having the same density range with the third impurity region isalso referred to as n-region. Moreover, the impurity element is notadded to the region covered by the masks 138 and 139 by the seconddoping processing, therefore, these become the first impurity regions145 and 146.

Subsequently, after the masks 137-139 consisted of the resists wereremoved, the masks 148-150 consisted of resists are newly formed, and asshown in FIG. 7 B, the third doping processing is performed.

In the drive circuit, the fourth impurity regions 151, 152 and the fifthimpurity regions 153, 154 in which the impurity element conferringp-type electrically conductive type to the semiconductor layer forforming p-channel type TFT and the semiconductor layer for formingretention volume has been added are formed by the above-described thirddoping processing.

Moreover, it is made so that the impurity element conferring p-type isadded to the fourth impurity regions 151, 152 in the range from 1×10²⁰to 1×10²¹/cm³. It should be noted that the fourth impurity regions 151,152 are the regions (n−-region) to which phosphorus (P) has been addedin the prior step, but its 1.5- to 3-fold density of impurity elementconferring p-type is added, and the electrically conductive type isp-type. Here, the region having the same density region with the fourthimpurity region is also referred to as p+ region.

Moreover, the fifth impurity regions 153, 154 are formed on the regionoverlapped with the tapered section of the second electricallyconductive layer 127 a, it is made so that the impurity elementconferring p-type is added in the density range from 1×10¹⁸ to1×10²⁰/cm³. Here, the region having the same density range with thefifth impurity region is also referred to as p-region.

Up to the above-described steps, the impurity regions having n-type orp-type electrically conductive type are formed on the respectivesemiconductor layers. The electrically conductive layers 126-129 becomegate electrodes of TFT. Moreover, the electrically conductive layer 130becomes one of the electrodes for forming the retention volume in thepixel section. Furthermore, the electrically conductive layer 131 formssource wirings in the pixel section.

Subsequently, an insulating film (not shown) for covering the nearlywhole surface is formed. In the present Example, a silicon oxide filmhaving film thickness of 50 nm has been formed by plasma CVD method.Needless to say, this insulating film is not limited to the siliconoxide film, another insulating film containing silicon may be used as amonolayer or a lamination structure.

Subsequently, the step for processing the activation of the impurityelements added to the respective semiconductor layers is carried out.This activation step is performed by rapid thermal annealing method (RTAmethod) using a lamp light source, or a method of irradiating YAG laseror excimer laser from the back side, or heat processing using a furnace,or a method combined with any method of these methods.

Moreover, in the present Example, although an example in which aninsulating film was formed before the above-described activation hasbeen shown, the step may be made a step in which after theabove-described activation was performed, the insulating film is formed.Subsequently, the first interlayer insulating film 155 consisted of asilicon nitride film is formed, the heat processing (heat processing at300-550° C. for 1-12 hours) is performed, and the step in which asemiconductor layer is hydrogenated (FIG. 7 C). This step is a step inwhich the dangling bond of the semiconductor layer is terminated byhydrogen contained in first interlayer insulating film 155. Thesemiconductor layer can be hydrogenated regardless of the existence ofthe insulating film (not shown) consisted of a silicon oxide film.However, since in the present Example, the materials whose principalcomponent is aluminum are used for the second electrically conductivelayer, it is important that the heat processing conditions are made sothat the second electrically conductive layer is endurable in the stepof hydrogenation. As the other means for hydrogenation, plasmahydrogenation (hydrogen excited by plasma is used) may be performed.

Subsequently, the second interlayer insulating film 156 consisted oforganic insulating material is formed on the first interlayer insulatingfilm 155. In the present Example, an acryl resin film having filmthickness of 1.61 μm is formed. Subsequently, a contact hole reachingthe source wiring 131, a contact hole reaching the electricallyconductive layers 129, 130 and a contact hole reaching the respectiveimpurity regions are formed. In the present Example, several etchingprocesses are in turn performed. In the present Example, after thesecond interlayer insulating film was etched by utilizing the firstinterlayer insulating film as an etching stopper, the insulating film(not shown) was etched following the first interlayer insulating filmwas etched by utilizing the insulating film (not shown). Then, thewirings and pixel electrodes are formed using Al, Ti, Mo, W and thelike. It is preferable that as for these materials for electrode andpixel electrode, a film whose principal component is Al or Ag, or amaterial excellent in reflecting properties such as a lamination ofthese or the like is used. Thus, source electrodes or drain electrodes157-162, a gate wiring 164, a connecting wiring 163, and a pixelelectrode 165 are formed.

As described above, a drive circuit 206 having a n-channel type TFT 201,a p-type channel type TFT 202 and a n-type channel type TFT 203, and apixel section 207 having a pixel TFT 204 consisted of a n-channel typeTFT and a retention volume 205 can be formed on the same substrate (FIG.8). In the present specification, such a substrate is referred to asactive matrix substrate for the sake of convenience.

On the pixel section 207, the pixel TFT 204 (n-channel type TFT) has achannel formation region 169, the first impurity region (n−-region) 147formed outside of the electrically conductive layer 129 forming a gateelectrode, and the second impurity regions (n+ region) 142, 171functioning as a source region or drain region. Moreover, the fourthimpurity region 152, the fifth impurity region 154 are formed on thesemiconductor layer functioning as one of the electrode of the retentionvolume 205. The retention volume 205 is formed with the second electrode130 and the semiconductor layers 152, 154 and 170 by utilizing theinsulating film (same film with gate insulating film) as a dielectric.

Moreover, in the drive circuit 206, the n-channel type TFT 201 (firstn-channel type TFT) has a channel formation region 166, the thirdimpurity region (n-region) 144 overlapped with one portion of theelectrically conductive layer 126 which forms a gate electrode via aninsulating film, and the second impurity region (n+ region) 140functioning as a source region or drain region.

Moreover, in the drive circuit 206, the p-channel type TFT 202 has achannel formation region 167, the fifth impurity region (p-region) 153overlapped with one portion of the electrically conductive layer 127which forms a gate electrode via an insulating film, and the fourthimpurity region (p+ region) 151 functioning as a source region or drainregion.

Moreover, in the drive circuit 206, the n-channel type TFT 203 (secondn-channel type TFT) has a channel formation region 168, the firstimpurity region (n−-region) 146 outside of the electrically conductivelayer 128 which forms a gate electrode, and the second impurity region(n+ region) 141 functioning as a source region or drain region.

A shift register circuit, a buffer circuit, a level shifter circuit, alatch circuit and the like are formed by appropriately combining theseTFTs 201-203, and the drive circuit 206 may be formed. For example, aCMOS circuit may be formed by complementarily connecting the n-channeltype TFT 201 and a p-channel type TFT 202. Particularly, for a buffercircuit whose drive voltage is high, for the purpose of preventing thedeterioration due to the hot carrier effect, the structure of an-channel type TFT 203 is suitable.

Moreover, for a circuit that the reliability is considered as the toppriority, the structure of a n-channel type TFT 201 which is a GOLDstructure is suitable.

Moreover, since the reliability can be enhanced by enhancing theflattening of the surface of a semiconductor film, in a TFT having aGOLD structure, a sufficient reliability can be obtained also bydiminishing the area of the impurity region overlapping with a gateelectrode via a gate insulating film. Concretely, in a TFT having a GOLDstructure, a sufficient reliability can be obtained by diminishing thesize of the portion which is a tapered section of a gate electrode.Moreover, in a TFT having a GOLD structure, when the gate insulatingfilm is thinner, the parasitic capacitance increases. However, the sizeof the portion which is a tapered section of the gate electrode (firstelectrically conductive layer) is made smaller, and the parasiticcapacitance is reduced, f characteristic (frequency characteristic) isalso enhanced and further a high operation is possible and the TFTobtained a sufficient reliability.

It should be noted that also in the pixel TFT of the pixel section 207,the reduction of OFF-state current and the reduction of the variationare realized by irradiation of the second laser beam.

Moreover, in the present Example, an example in which an active matrixsubstrate for forming a reflective type display device is prepared isshown, but when the pixel electrode is formed by a transparentelectrically conductive film, although the number of photo-masksincreases by one sheet, a transparent type display device can be formed.

Moreover, in the present Example, a glass substrate was used, but it isnot particularly limited. A quartz substrate, a semiconductor substrate,a ceramic substrate, and a metal substrate can be used.

Moreover, after the state of FIG. 8 was obtained, if the layer (peeledoff layer) containing a TFT provided on the oxide layer 102 has asufficient mechanical strength, the substrate 100 may be pulled away. Inthe present Example, since the mechanical strength of the peeled-offlayer is not sufficient, it is preferred that after the supporting body(not shown) for fixing the peeled-off layer was pasted, it is peeledoff.

Example 2

In the present Example, the step in which an active matrix type liquidcrystal display device is prepared by peeling off the substrate 100 fromthe active matrix substrate prepared in Example 1 and pasting it with aplastic substrate will be described below. FIG. 9 is used for thepurpose of describing it.

In FIG. 9 A, the reference numeral 400 denotes a substrate, thereference numeral 401 denotes a nitride layer or metal layer, thereference numeral 402 denotes an oxide layer, the reference numeral 403denotes a primary coat insulating layer, the reference numeral 404 adenotes an element of a drive circuit 413, the reference numeral 404 bdenotes an element 404 b of the pixel section 414 and the referencenumeral 405 denotes a pixel electrode. Here, the term “element” isreferred to a semiconductor element (typically, TFT) or MIM element orthe like used for a switching element of pixels in an active matrix typeliquid crystal display device. An active matrix substrate shown in FIG.9 A is shown as simplifying the active matrix substrate shown in FIG. 8,the substrate 100 in FIG. 8 corresponds to the substrate 400 in FIG. 9A. Similarly, the reference numeral 401 in FIG. 9 A corresponds to thereference numeral 101 in FIG. 8, the reference numeral 402 in FIG. 9 Acorresponds to the reference numeral 102 in FIG. 8, the referencenumeral 403 in FIG. 9 A corresponds to the reference numeral 103 in FIG.8, the reference numeral 404 a in FIG. 9 A corresponds to the referencenumerals 201 and 202 in FIG. 8, the reference numeral 404 b in FIG. 9 Acorresponds to the reference numeral 204 in FIG. 8, and the referencenumeral 405 in FIG. 9 A corresponds to the reference numeral 165 in FIG.8, respectively.

First, according to Example 1, after the active matrix substrate of thestate in FIG. 8 was obtained, an orientation film 406 a is formed on theactive matrix substrate of FIG. 8, and a rubbing processing isperformed. It should be noted that in the present Example, before theorientation film is formed, a spacer in a column shape (not shown) forretaining a substrate interval was formed at the desired position bypatterning an organic resin film such as an acryl resin or the like.Moreover, instead of a spacer in a column shape, a spacer in a sphereshape may be scattered over the whole surface of the substrate.

Subsequently, an opposing substrate which is to be a supporting body 407is prepared for. A color filter (not shown) in which a colored layer anda radiation shield layer were arranged corresponding to the respectivepixels has been provided on this opposing substrate. Moreover, aradiation shield was provided on the portion of the drive circuit. Aflattening film (not shown) for covering this color filter and theradiation shield layer was provided. Subsequently, an opposing electrode408 consisted of a transparent electrically conductive film was formedon the flattening film in the pixel section, an orientation film 406 bwas formed on the whole surface of the opposing substrate, and therubbing processing was provided.

Then, an active matrix substrate 400 in which the pixel section and thedrive circuit were formed and the supporting body 407 are pastedtogether with a sealing medium which is to be an adhesive layer 409.Into a sealing medium, filler is mixed, two sheets of substrates arepasted together with uniform interval by this filler and a spacer in acolumn shape. Then, between both substrates, a liquid crystal material410 is implanted and completely sealed with a sealing compound (notshown) (FIG. 9 B). As a liquid crystal material 410, the known liquidcrystal material may be used.

Subsequently, the substrate 400 on which the nitride layer or metallayer 401 has been provided is pulled away by the physical means (FIG. 9C). Since the film stress of the oxide layer 402 and the film stress ofthe nitride layer or metal layer 401 are different, these can be pulledaway by comparatively small force. Subsequently, it is pasted with anadhesive layer 411 consisted of an epoxy resin or the like on atransferring body 412. In the present Example, it can be made light byusing plastic film substrate for the transferring body 412.

In this way, a flexible active matrix type liquid crystal display deviceis completed. Then, if necessary, the flexible substrate 412 or anopposing substrate is cut down in the desired shape. Furthermore, apolarizing plate (not shown) or the like was appropriately providedusing the known technology. Then, a FPC (not shown) was pasted using theknown technology.

Example 3

In the Example 2, an example in which after an opposing substrate as asupporting body was pasted and a liquid crystal was implanted, thesubstrate was peeled off and a plastic substrate was pasted as atransferring body was shown. However, in the present Example, an examplein which after an active matrix substrate shown in FIG. 8 was formed,the substrate was peeled off, and the plastic substrate as the firsttransferring body and the plastic substrate as the second transferringbody was pasted together will be described. FIG. 10 will be used for thepurpose of describing it.

In FIG. 10 A, the reference numeral 500 denotes a substrate, thereference numeral 501 denotes a nitride layer or metal layer, thereference numeral 502 denotes an oxide layer, the reference numeral 503denotes a primary coat insulating layer, the reference numeral 504 adenotes an element of a drive circuit 514, the reference numeral 504 bdenotes an element {504 b?} of the pixel section 515 and the referencenumeral 505 denotes a pixel electrode. An active matrix substrate shownin FIG. 10 A is shown as one simplifying the active matrix substrateshown in FIG. 8, the substrate 100 in FIG. 8 corresponds to thesubstrate 500 in FIG. 10 A. Similarly, the reference numeral 501 in FIG.10 A corresponds to the reference numeral 101 in FIG. 8, the referencenumeral 502 in FIG. 10 A corresponds to the reference numeral 102 inFIG. 8, the reference numeral 503 in FIG. 10 A corresponds to thereference numeral 103 in FIG. 8, the reference numeral 504 a in FIG. 10A corresponds to the reference numerals 201 and 202 in FIG. 8, thereference numeral 504 b in FIG. 10 A corresponds to the referencenumeral 204 in FIG. 8, and the reference numeral 505 in FIG. 10 Acorresponds to the reference numeral 165 in FIG. 8, respectively.

First, according to Example 1, after an active matrix substrate in thestate of FIG. 8 was obtained, the substrate 500 on which the nitridelayer or metal layer 501 has been provided is pulled away by thephysical means (FIG. 10 B). Since the film stress of the oxide layer 502and the film stress of the nitride layer or metal layer 501 aredifferent, these can be pulled away by a comparatively small force.

Subsequently, it is pasted with an adhesive layer 506 consisted of anepoxy resin or the like on a transferring body 507(first transferringbody). In the present Example, it can be made light by using plasticfilm substrate for the transferring body 507 (FIG. 10C). Subsequently,an orientation film 508 a is formed and a rubbing processing isperformed. It should be noted that in the present Example, before theorientation film is formed, a spacer in a column shape (not shown) forretaining a substrate interval was formed at the desired position bypatterning an organic resin film such as an acryl resin or the like.Moreover, instead of a spacer in a column shape, a spacer in a sphereshape may be scattered over the whole surface of the substrate.Subsequently, an opposing substrate which is to be a supporting body 510(second transferring body) is prepared for. A color filter (not shown)in which a colored layer and a radiation shield layer were arrangedcorresponding to the respective pixels has been provided on thisopposing substrate. Moreover, a radiation shield was provided on theportion of the drive circuit. A flattening film (not shown) for coveringthis color filter and the radiation shield layer was provided.Subsequently, an opposing electrode 509 consisted of a transparentelectrically conductive film was formed on the flattening film in thepixel section, an orientation film 508 b was formed on the whole surfaceof the opposing substrate, and the rubbing processing was provided.

Then, a plastic film substrate 507 in which the pixel section and thedrive circuit were adhered and the supporting body 510 are pastedtogether with a sealing medium which is to be an adhesive layer 512(FIG. 10 D). Filler is mixed into sealing medium, and two sheets ofsubstrates are pasted together with uniform interval by this filler anda spacer in a column shape. Then, between both substrates, a liquidcrystal material 513 is implanted and completely sealed with a sealingcompound (not shown) (FIG. 10 D). As a liquid crystal material 513, theknown liquid crystal material may be used.

In this way, a flexible active matrix type liquid crystal display deviceis completed. Then, if necessary, the flexible substrate 507 or anopposing substrate is cut in the desired shape. Furthermore, apolarizing plate (not shown) or the like was appropriately providedusing the known technology. Then, a FPC (not shown) was pasted using theknown technology.

Example 4

The structure of the liquid crystal module obtained by Example 2 orExample 3 is described with reference to the top view in FIG. 11. Asubstrate 412 in Example or a substrate 507 in Example 3 corresponds toa substrate 301.

A pixel portion 304 is placed in the center of a substrate 301. A sourcesignal line driving circuit 302 for driving source signal lines ispositioned above the pixel portion 304. Gate signal line drivingcircuits 303 for driving gate signal lines are placed to the left andright of the pixel portion 304. Although the gate signal line drivingcircuits 303 are symmetrical with respect to the pixel portion in thisExample, the liquid crystal module may have only one gate signal linedriving circuit on one side of the pixel portion. Of the above twooptions, a designer can choose the arrangement that suits betterconsidering the substrate size or the like of the liquid crystal module.However, the symmetrical arrangement of the gate signal line drivingcircuits shown in FIG. 11 is preferred in terms of circuit operationreliability, driving efficiency, and the like.

Signals are inputted to the driving circuits from flexible printedcircuits (FPC) 305. The FPCs 305 are press-fit through an anisotropicconductive film or the like after opening contact holes in theinterlayer insulating film and resin film and forming a connectionelectrode 309 so as to reach the wiring lines arranged in given placesof the substrate 301. The connection electrode is formed from ITO inthis Example.

A sealing agent 307 is applied to the substrate along its perimetersurrounding the driving circuits and the pixel portion. An oppositesubstrate 306 is bonded to the substrate 301 by the sealing agent 307while a spacer formed in advance on the film substrate keeps thedistance between the two substrates constant. A liquid crystal elementis injected through an area of the substrate that is not coated with thesealing agent 307. The substrates are then sealed by an encapsulant 308.The liquid crystal module is completed through the above steps.

Although all of the driving circuits are formed on the film substrate inthe example shown here, several ICs may be used for some of the drivingcircuits. This Example may be combined with Example 1.

Example 5

Example 1 shows an example of reflective display device in which a pixelelectrode is formed from a reflective metal material. Shown in thisExample is an example of transmissive display device in which a pixelelectrode is formed from alight-transmitting conductive film.

The manufacture process up through the step of forming an interlayerinsulating film is identical with the process of Example 1, and thedescription thereof is omitted here. After the interlayer insulatingfilm is formed in accordance with Example 1, a pixel electrode 601 isformed from a light-transmitting conductive film. Examples of thelight-transmitting conductive film include an ITO (indium tin oxidealloy) film, an indium oxide-zinc oxide alloy (In₂O₃—ZnO) film, a zincoxide (ZnO) film, and the like.

Thereafter, contact holes are formed in an interlayer insulating film600. A connection electrode 602 overlapping the pixel electrode isformed next. The connection electrode 602 is connected to a drain regionthrough the contact hole. At the same time the connection electrode isformed, source electrodes or drain electrodes of other TFTs are formed.

Although all of the driving circuits are formed on the substrate in theexample shown here, several ICs may be used for some of the drivingcircuits.

An active matrix substrate is completed as above. After peeling thesubstrate by using this active matrix substrate to bond plasticsubstrates, a liquid crystal module is manufactured in accordance withExamples 2 to 4. The liquid crystal module is provided with a backlight604 and a light guiding plate 605, and is covered with a cover 606 tocomplete the active matrix liquid crystal display device of which apartial sectional view is shown in FIG. 12. The cover is bonded to theliquid crystal module using an adhesive or an organic resin. Whenbonding the plastic substrate to the opposite substrate, the substratesmay be framed so that the space between the frame and the substrates isfilled with an organic resin for bonding. Since the display device is oftransmissive type, the plastic substrate and the opposite substrate eachneeds a polarizing plate 603 to be bonded.

This Example may be combined with Examples 1 to 4.

Example 6

In the present Example, an example in which a light emitting devicehaving an organic light emitting device (OLED) formed on a plasticsubstrate is prepared is shown in FIG. 13.

In FIG. 13 A, the reference numeral 600 denotes a substrate, thereference numeral 601 denotes a nitride layer or metal layer, thereference numeral 602 denotes an oxide layer, the reference numeral 603denotes a primary coat insulating layer, the reference numeral 604 adenotes an element of a drive circuit 611, the reference numeral 604 band 604 c denote an element {504 b?} of the pixel section 612 and thereference numeral 605 denotes an OLED (Organic Light Emitting Device).Here, the term “element” is referred to a semiconductor element(typically, TFT) or MIM element or the like used for a switching elementof pixels if it is an active matrix type liquid crystal display device.Then, an interlayer insulating film 606 which covers these elements isformed. It is preferred that the interlayer insulating film 606 isflatter than the surface after the film formation. It should be notedthat the interlayer insulating film 606 is not necessarily provided.

It should be noted that the reference numerals 601-603 provided on thesubstrate 600 may be formed according to Embodiment 2 through 4.

These elements (including 604 a, 604 b and 604 c) may be preparedaccording to the n-channel type TFT 201 of the above-described Example 1and/or the p-channel type TFT 202 of the above-described Example 1.

An OLED 605 has a layer containing an organic compound (organic lightemitting material) obtaining electroluminescence generating by addingelectric field (hereinafter, referred to as organic light emittinglayer), an anode layer and a cathode layer. Although as forelectroluminescence in organic compounds, there are a luminescence(fluorescence) generated when returning from singlet excitation state toground state and a luminescence (phosphorescence) generated whenreturning from triplet state to ground state, a light emitting device ofthe present invention may use either of the above-describedluminescences or both the above-described luminescences. It should benoted that in the present specification, all of the layers formedbetween the anode and cathode of OLED are defined as an organic lightemitting layer. Concretely, organic light emitting layers include alight emitting layer, a hole injection layer, an electronic injectionlayer, a hole transport layer, an electron transport layer or the like.Fundamentally, OLED has a structure in which anode/light emittinglayer/cathode are in turn laminated, in addition to this structure,there may be also some structures having anode/hole injectionlayer/light emitting layer/cathode or anode/hole injection layer/lightemitting layer/electron transport layer/cathode or the like are in turnlaminated. According to the above-described method, the state of FIG. 13A was obtained, the supporting body 608 is pasted using the adhesivelayer 607 (FIG. 13B). In the present Embodiment, aplastic substrate isused as the supporting body 608. Concretely, as a supporting body, aresin substrate having thickness of 10 μm or more, for example,poly(ether sulfone) (PES), polycarbonate (PC), polyethyleneterephthalate (PET), or polyethylene naphthalate (PEN) can be used. Itshould be noted that it is required when the supporting body 608 and theadhesive layer 607 are located at the observer's side (on the side ofthe user of the light emitting device) seen from the OLED, thesupporting body 608 and the adhesive layer 607 are materials whichtransmits the light.

Subsequently, the substrate 600 on which the nitride layer or metallayer 601 has been provided is pulled away by the physical means (FIG.13 C). Since the film stress of the oxide layer 602 and the film stressof the nitride layer or metal layer 601 are different, these can bepulled away by a comparatively small force. Subsequently, it is pastedwith an adhesive layer 609 consisted of an epoxy resin or the like on atransferring body 610 (FIG. 13 D). In the present Example, it can bemade light by using plastic film substrate for the transferring body610.

In this way, a flexible light emitting device sandwiched between thesupporting body 608 having the flexibility and the transferring body 610having the flexibility can be obtained. It should be noted that if thesupporting body 608 and the transferring body 610 are made of the samematerial, the coefficients of thermal expansion become equal, therefore,the influence from the stress distortion due to the change oftemperature can be made not easily exerted.

Then, if necessary, the supporting body 608 having the flexibility andthe transferring body 610 are cut in the desired shape. Then, a FPC (notshown) was pasted using the known technology.

Example 7

In Example 6, an example in which after the supporting body was pasted,the substrate was peeled off and a plastic substrate as a transferringbody was pasted has been shown. However, in the present Example, anexample in which after the substrate was peeled off, a plastic substrateas the first transferring body and a plastic substrate as the secondtransferring body are pasted and a light emitting device equipped withan OLED is prepared will be shown. FIG. 14 will be made reference forthe purpose of describing it.

In FIG. 14A, the reference numeral 700 denotes a substrate, thereference numeral 701 denotes a nitride layer or metal layer, thereference numeral 702 denotes an oxide layer, the reference numeral 703denotes a primary coat insulating layer, the reference numeral 704 adenotes an element of a drive circuit 711, the reference numerals 704 b,704 c denote an element of the pixel section 712 and the referencenumeral 705 denotes an OLED (Organic Light Emitting Device). Here, theterm “element” is referred to a semiconductor element (typically, TFT)or MIM element or the like used for a switching element of pixels if itis an active matrix type liquid crystal display device. Then, aninterlayer insulating film 706 which covers these elements is formed. Itis preferred that the interlayer insulating film 706 is flatter than thesurface after the film formation. It should be noted that the interlayerinsulating film 706 is not necessarily provided.

It should be noted that the reference numerals 701-703 provided on thesubstrate 700 might be formed according to any of Embodiment 2 through4.

These elements (including 704 a, 704 b and 704 c) may be preparedaccording to the n-channel type TFT 201 of the above-described Example1, the p-channel type TFT 202 of the above-described Example 1.

According to the above-described method, the state of FIG. 14 A wasobtained, the substrate 700 on which the nitride layer or metal layer701 has been provided is pulled away by the physical means (FIG. 14 B).Since the film stress of the oxide layer 702 and the film stress of thenitride layer or metal layer 701 are different, these can be pulled awayby comparatively small force. Subsequently, it is pasted with anadhesive layer 709 consisted of an epoxy resin or the like on atransferring body (first transferring body) 710. In the present Example,it can be made light by using plastic film substrate for thetransferring body 710.

Subsequently, the base member (second transferring body) 708 is pastedtogether by the adhesive layer 707 (FIG. 14 C). In the presentEmbodiment, a plastic substrate is used as the supporting body 708.Concretely, as the transferring body 710 and the base member 708, aresin substrate having thickness of 10 μm or more, for example,poly(ether sulfone) (PES), polycarbonate (PC), polyethyleneterephthalate (PET), or polyethylene naphthalate (PEN) can be used. Itshould be noted that it is required in the case where the base member708 and the adhesive layer 707 are located at the observer's side (onthe side of the user of the light emitting device) seen from the OLED,the base member 708 and the adhesive layer 707 are materials whichtransmit the light. In this way, a flexible light emitting devicesandwiched between the base member 708 having the flexibility and thetransferring body 710 having the flexibility can be obtained. It shouldbe noted that if the base member 708 and the transferring body 710 aremade of the same material, the coefficients of thermal expansion becomeequal, therefore, the influence from the stress distortion due to thechange of temperature can be made not easily exerted.

Then, if necessary, the base member 708 having the flexibility and thetransferring body 710 are cut in the desired shape. Then, a FPC (notshown) was pasted using the known technology.

Example 8

In Example 6 or Example 7, an example in which a flexible light emittingdevice sandwiched between substrates having the flexibility is obtainedhas been shown. However, since a substrate consisted of a plastic ingeneral easily transmits water content and oxygen, and the deteriorationof an organic light emitting layer is promoted by these, the life-spanof the light emitting device easily tends to be shorter.

Hence, in the present Example, on a plastic substrate, a plurality offilms for preventing oxygen and water content from penetrating into theorganic light emitting layer of OLED (hereinafter, referred to asbarrier film) and a layer (stress relaxation film) having a smallerstress than the foregoing barrier film between the foregoing barrierfilms each other are provided. In the present specification, a film inwhich a barrier film and a stress relaxation film are laminated isreferred to as “sealing film”.

Concretely, two or more layers of barrier films consisted of inorganicmatters (hereinafter, referred to as barrier film) are provided, andfurther, a stress relaxation film having a resin between the relevanttwo-layer barrier films (hereinafter, referred to as stress relaxationfilm) is provided. Then, a light emitting device is formed by forming anOLED on the relevant three or more-layer insulating film and tightlysealing. It should be noted that since Example 6 and Example 7 are thesame except for the substrate, here, the description on them is omitted.

As shown in FIG. 15, two or more layers of barrier films are provided onthe film substrate 810, and further, a stress relaxation film isprovided between the relevant two-layer barrier films. As a result,between the film substrate 810 and the second adhesive layer 809, asealing film in which the relevant barrier film and the stressrelaxation film are laminated is formed.

Here, a layer consisted of a silicon nitride is film-formed as a barrierfilm 811 a on the film substrate 810 by a sputtering method, a stressrelaxation film 811 b having polyimide is film-formed on the barrierfilm 811 a, a layer consisted of a silicon nitride is film-formed as thebarrier film 811 c on the stress relaxation film 811 b by a sputteringmethod. A layer in which the barrier film 811 a, the stress relaxationfilm 811 b, and the barrier film 811 c are laminated is generallyreferred to as the sealing film 811. Then the film substrate 810 onwhich the relevant sealing film 811 is formed may be pasted togetherusing the second adhesive layer 809 on the peeled layer containing anelement.

Similarly, a layer consisted of a silicon nitride is formed as a barrierfilm 814 a on the film substrate 812 by a sputtering method, and astress relaxation film 814 b having polyimide is formed on the barrierfilm 814 a. A layer consisted of a silicon nitride is formed as thebarrier film 814 c on the stress relaxation film 814 b by a sputteringmethod. A layer in which the barrier film 814 a, the stress relaxationfilm 814 b, and the barrier film 814 c are laminated is generallyreferred to as the sealing film 814. Then the film substrate 812 onwhich the relevant sealing film 814 is formed may be pasted togetherusing the second adhesive layer 809 on the peeled layer containing anelement.

It should be noted that as for a barrier film, if two layers or more areprovided, it might be available. Then, as a barrier film, a siliconnitride, a silicon oxynitride, an aluminum oxide, an aluminum nitride,an aluminum oxynitride or an aluminum silicide oxynitride (AlSiON) canbe used.

Since an aluminum silicide oxynitride is comparatively high in thermalconductivity, the heat generated in an element can be efficientlydischarged by utilizing it as a barrier film.

Moreover, for a stress relaxation film, a resin having a transparencycan be used. Representatively, polyimide, acryl, polyamide,polyimideamide, benzocyclobutene, epoxy resin or the like is capable ofbeing used. It should be noted that resins except for resins describedabove could be also used. Here, after polyimide which is a typethermally polymerized was coated, it is burned and formed.

The film formation of a silicon nitride is performed at 0.4 Pa ofsputtering pressure by introducing argon, maintaining the substratetemperature as 150° C. Then, using a silicon as a target, the filmformation was performed by introducing nitrogen and hydrogen except forargon. In the case of a silicon oxynitride, the film formation isperformed at about 0.4 Pa of sputtering pressure by introducing argonand maintaining the substrate temperature as 150° C. Then, using asilicon as a target, the film formation was performed by introducingnitrogen, nitrogen dioxide and hydrogen except for argon. It should benoted that as a target, a silicon oxide might be used.

It is desirable that the film thickness of the barrier film is in therange from 50 nm to 3 μm. Here, a silicon nitride was formed in filmthickness of 1 μm.

It should be noted that the film formation method of a barrier film isnot limited only to sputtering method, the person who carries out it canappropriately set its method. For example, the film formation may beperformed using a LPCVD method, a plasma CVD method or the like.Moreover, it is desirable that the film thickness of the stressrelaxation film is in the range from 200 nm to 2 μm. Here, polyimide wasformed in film thickness of 1 μm.

An OLED can be completely interrupted from the air by applying a plasticsubstrate on which a sealing film of the present Example is provided asthe supporting body 608 or the transferring body 610 in Example 6 or thebase member 708 or the transferring body 710 in Example 7, therebycapable of nearly completely suppressing the deterioration of an organiclight emitting material due to oxidation, and capable of largelyenhancing the reliability of an OLED.

Example 9

The constitution of a module having an OLED obtained according toExample 6 or Example 7, what is called the constitution of an EL modulewill be described below with reference to a top view of FIG. 16. Thetransferring body 610 in Example 7 or the transferring body 710 inExample 8 corresponds to the film substrate 900. FIG. 16 A is atop viewshowing a module having an OLED, what is called an EL module, and FIG.16 B is a sectional view taken on line A-A′ of FIG. 16 A. A pixelsection 902, the source side drive circuit 901 and the gate side drivecircuit 903 are formed on a film substrate 900 (for example, plasticsubstrate or the like) having the flexibility. These pixel section anddrive circuit can be obtained according to the above-described Example.Moreover, the reference numeral 918 denotes a sealing member, thereference numeral 919 denotes a DLC film, the pixel section and thedrive circuit section are covered by the sealing member 918, and itssealing member is covered with the protective film 919. Furthermore, itis sealed with a cover member 920 using an adhesive member. The shape ofthe covering member 920 and the shape of the supporting body are notparticularly limited, one having a plane, one having a curved surface,and one having a property capable of being curved, or one in a filmshape may be used. It is desirable that the covering member 920 forenduring the distortion due to the heat and external force is the samematerial with the film substrate 900, for example, a plastic substrateis used, the substrate processed in a concave section shape (depth, 3-10μm) as shown in FIG. 16 is used. It is desirable that it is furtherprocessed, and a concave section (depth, 50-200 μm) on which desiccant921 can be set is formed. Moreover, in the case where an EL module isfabricated in multiple pattern, after the substrate and the coveringmember were pasted together, it may be cut so that the end faces arematched with each other using Co₂ laser or the like.

Moreover, here not shown in Figs., in order to prevent the backgroundfrom being reflected due to the reflection of the applied metal layer(here, cathode or the like), a circular polarizing means referred to asa circular polarizing plate consisted of a phase difference plate (λ/4plate) and polarizing plate may be provided on the substrate 900.

It should be noted that the reference numeral 908 denotes a wiring fortransmitting a signal inputted into the source side drive circuit 901and the gate side drive circuit 903, it receives a video signal and aclock signal from FPC (Flexible Print Circuit) which is an externalinput terminal. Moreover, a light emitting device of the present Examplemay be of a digital drive, or an analog drive, or a video signal may bea digital signal, or an analog signal. It should be noted that here,only FPC is shown in Figs., but a print wiring base (PWB) may be mountedon this FPC. It is defined that a light emitting device in the presentspecification includes not only the main body of the light emittingdevice but also the state where FPC or PWB is mounted on the main body.Moreover, although a complex integrated circuit (memory, CPU,controller, D/A converter or the like) are capable of being formed onthe same substrate with these pixel section and drive circuit, thefabrication with a small number of masks is difficult. Therefore, it ispreferred that an IC chip equipped with a memory, a CPU, a controller, aD/A converter or the like is mounted by COG (Chip On Glass) method, orTAB (Tape Automated Bonding) method or a wire bonding method.

Next, the sectional structure will be described below with reference toFIG. 16 B. An insulating film 910 is provided on the film substrate 900,the pixel section 902 and the gate side drive circuit 903 have beenformed above the insulating film 910, and the pixel section 902 isformed by a plurality of pixels containing the pixel electrode 912electrically connected to the TFT 911 for controlling the current andits drain. It should be noted that after the peeled off layer formed onthe substrate was peeled off according to any one of Embodiment 1through 4, the film substrate 900 is pasted.

Moreover, the gate side drive circuit 903 is formed using a CMOS circuitthat a n-channel type TFT 913 and a p-channel type TFT 914 are combined.

These TFTs (including 911, 913 and 914) may be fabricated according tothe n-channel type TFT 201 of the above-described Example 1, thep-channel type TFT 202 of the above-described Example 1.

It should be noted that as an insulating film provided between the TFTand OLED, it is preferable that a material for not only blocking thediffusion of the impurity ion such as alkali metal ion, alkaline earthmetal ion or the like, but also aggressively absorbing the impurity ionsuch as alkali metal ion, alkaline earth metal ion or the like, andfurther, a material endurable for the temperature of later processes issuitable. As a material suitable for these conditions, as one example, asilicon nitride film containing a large amount of fluorine is listed.The fluorine density containing in the film of the silicon nitride filmis 1×10¹⁹/cm³ or more, preferably, the composition ratio of fluorine ismade in the range from 1 to 5%. The fluorine in the silicon nitride filmis bonded to alkali metal ion, alkaline earth ion or the like, andabsorbed in the film. Moreover, as the other example, an organic resinfilm containing a fine particle consisted of antimony (Sb) compound, tin(Sn) compound or indium (In) compound, for example, an organic resinfilm containing antimony pentaoxide fine particle (Sb₂O₅.nH₂O) is alsolisted. It should be noted that this organic resin film contains a fineparticle having 10-20 nm in average particle diameter, and lighttransmittance is also very high. An antimony compound represented bythis antimony pentaoxide fine particle easily absorbs impurity ion suchas alkali metal ion or alkaline earth metal ion.

Moreover, as the other material of an insulating film provided betweenthe active layer of TFT and the OLED, a layer indicated by AlN_(x)O_(y)may be used. An oxynitride layer (layer indicated by AlN_(x)O_(y))obtained by performing the film formation under the atmosphere thatargon gas, nitride gas, nitrogen gas and oxygen gas are mixed usingaluminum nitride (AlN) target by a sputtering method is a filmcontaining nitrogen in the range from 2.5 atm % to 47.5 atm %,characterized by the fact that it has an effect capable of blockingwater content and oxygen, in addition to this, has a high thermalconductivity and an effect of heat release, and further, has a very hightranslucency. In addition, it can prevent impurities such as alkalimetal, alkaline earth metal or the like from penetrating into the activelayer of TFT.

The pixel electrode 912 functions as an anode of the OLED. Moreover, abank 915 is formed on both ends of the pixel electrode 912, an EL layer916 and a cathode 917 of the light emitting element are formed on thepixel electrode 912.

As the EL layer 916, an EL layer (layer for light emitting and makingcarrier perform the migrate for it) may be formed by freely combiningthe light emitting layer, a charge injection layer or a chargeimplantation layer. For example, low molecular system organic ELmaterial and high molecular system organic EL material may be employed.Moreover, as an EL layer, a thin film consisted of a light emittingmaterial (singlet compound) which light-emits (fluorescence) due tosinglet excitation, or a thin film consisted of a light emittingmaterial (triplet compound) which emits (phosphorescence) due to tripletexcitation can be used. Moreover, an inorganic material such as siliconcarbide or the like is capable of being used as a charge transport layerand a charge injection layer. For these organic EL material andinorganic material, the known materials can be used. The cathode 917also functions the wiring common to the all of the pixels, andelectrically connected to the FPC 909 via the connecting wiring 908. Andfurther, elements contained in the pixel section 902 and on the gateside drive circuit 903 are all covered by the cathode 917, the sealingmember 918, and the protective film 919.

It should be noted that as the sealing member 918, it is preferable thata material being transparent to the visible light or semitransparent isused if it is possible. Moreover, it is desirable that the sealingmember 918 is a material for transmitting water content and oxygen aslittle as possible.

Moreover, after the light emitting element was completely covered byutilizing the sealing member 918, it is preferred that the protectivefilm 919 consisted of at least DLC film or the like is provided on thesurface (exposed surface) of the sealing member 918 as shown in FIG. 16.Moreover, the protective film may be provided on the entire surfaceincluding the back side of the substrate. Here, it is necessary to noteso that the protective film is not formed on the portion on which theexternal input terminal (FPC) is provided. It may be made so that theprotective film is not formed by utilizing a mask, or it may be made sothat the protective film is not formed by covering the exterior inputterminal portion with a tape such as a masking tape used in a CVDdevice.

The light emitting element can be completely interrupted from theexternal by sealing the light emitting element with the sealing member918 and the protective film in the above-described structure, and it canprevent the substances promoting the deterioration due to the oxidationof EL layer occurred by water content, oxygen or the like from theexternal from penetrating. In addition to this, if a film having athermal conductivity (AlON film, AlN film or the like) is used as aprotective film, the heat generated when it is driven can be released.Therefore, a light emitting device with high reliability can beobtained.

Moreover, the pixel electrode is made a cathode, the EL layer and theanode are laminated and it may be configured so that the light isemitted in the reverse direction. Its one example is shown in FIG. 17.It should be noted that since a top view is the same, the diagram anddescription are omitted.

The sectional structure shown in FIG. 17 will be described below. As afilm substrate 1000, a plastic substrate is used. It should be notedthat after the peeled off layer formed on the substrate was peeled offaccording to any one of Embodiment 1 through 4, the film substrate 1000is pasted. An insulating film 1010 is provided on the film substrate1000, above the insulating film 1010, the pixel section 1002 and thegate side drive circuit 1003 are formed and the pixel section 1002 isformed by a plurality of pixels containing a pixel electrode 1012electrically connected to a TFT for controlling the current 1011 and itsdrain. Moreover, the gate side drive circuit 1003 is formed using a CMOScircuit that a n-channel type TFT 1013 and a p-channel type TFT 1014 arecombined.

The pixel electrode 1012 functions as a cathode of the light emittingelement. Moreover, a bank 1015 is formed on both ends of the pixelelectrode 1012, an EL layer 1016 and an anode 1017 of the light emittingelement are formed on the pixel electrode 1012.

The anode 1017 also functions as the common wiring to all of the pixels,and electrically connected to the FPC 1009 via a connecting wiring 1008.Furthermore, the element contained in the pixel section 1002 and thegate side drive circuit 1003 are all covered by the protective film 1019consisted of the anode 1017, the sealing member 1018 and DLC or thelike. Moreover, the covering member 1021 and the substrate 1000 werepasted using the adhesive. Moreover, the concave portion is provided onthe covering member, and the desiccant 1021 is set on the coveringmember.

It should be noted that as the sealing member 1018, it is preferablethat a material being transparent to the visible light orsemitransparent is used if it is possible. Moreover, it is desirablethat the sealing member 1018 is a material for transmitting watercontent and oxygen as little as possible.

Moreover, in FIG. 17, since the pixel electrode was made cathode, andthe EL layer and the anode were laminated, the direction of the lightemission is a direction of the arrow indicted in FIG. 17.

Moreover, here not shown in Figs., in order to prevent the backgroundfrom being reflected due to the reflection of the applied metal layer(here, cathode or the like), a circular polarizing means referred to asa circular polarizing plate consisted of a phase difference plate (λ/4plate) and polarizing plate may be provided on the covering member 1020.

Since in the present Example 1, a TFT having a highly qualified electriccharacteristics and a high reliability obtained in Example 1 is used, alight emitting element having a higher reliability comparing to those ofthe conventional elements can be formed. Moreover, an electric apparatushaving a high performance can be obtained by utilizing a light emittingdevice having such light emitting elements as a display section.

It should be noted that the present Example could be freely combinedwith Example 1, Example 7, Example 8 or Example 9.

The present invention can enhance the reliability of an element withoutdamaging the semiconductor layer since peeling off from the substrate bythe physical means.

Moreover, the present invention is capable of peeling off not only apeeled off layer having a small area but also a peeled off layer havinga large area over the entire surface at excellent yield ratio.

In addition, since the present invention is capable of easily peelingoff by the physical means, for example, is capable of pulling away byhuman's hands, it can be said that the process is suitable for massproduction. Moreover, in the case where a manufacturing equipment isprepared in order to pull away the peeled off layer when performing themass production, a large size fabrication equipment can also be preparedat low cost.

Example 10

Various modules (active matrix liquid crystal module, active matrix ELmodule and active matrix EC module) can be completed by the presentinvention. Namely, all of the electronic apparatuses are completed byimplementing the present invention.

Following can be given as such electronic apparatuses: video cameras;digital cameras; head mounted displays (goggle type displays); carnavigation systems; projectors; car stereo; personal computers; portableinformation terminals (mobile computers, mobile phones or electronicbooks etc.) etc. Examples of these are shown in FIGS. 18 and 19.

FIG. 18A is a personal computer which comprises: a main body 2001; animage input section 2002; a display section 2003; and a keyboard 2004.

FIG. 18B is a video camera which comprises: a main body 2101; a displaysection 2102; a voice input section 2103; operation switches 2104; abattery 2105 and an image receiving section 2106.

FIG. 18C is a mobile computer which comprises: a main body 2201; acamera section 2202; an image receiving section 2203; operation switches2204 and a display section 2205.

FIG. 18D is a goggle type display which comprises: a main body 2301; adisplay section 2302; and an arm section 2303.

FIG. 18E is a player using a recording medium which records a program(hereinafter referred to as a recording medium) which comprises: a mainbody 2401; a display section 2402; a speaker section 2403; a recordingmedium 2404; and operation switches 2405. This apparatus uses DVD(digital versatile disc), CD, etc. for the recording medium, and canperform music appreciation, film appreciation, games and use forInternet.

FIG. 18F is a digital camera which comprises: a main body 2501; adisplay section 2502; a view finder 2503; operation switches 2504; andan image receiving section (not shown in the figure).

FIG. 19A is a portable telephone which comprises: a main body 2901; avoice output section 2902; a voice input section 2903; a display section2904; operation switches 2905; an antenna 2906; and an image inputsection (CCD, image sensor, etc.) 2907 etc.

FIG. 19B is a portable book (electronic book) which comprises: a mainbody 3001; display sections 3002 and 3003; a recording medium 3004;operation switches 3005 and an antenna 3006 etc.

FIG. 19C is a display which comprises: a main body 3101; a supportingsection 3102; and a display section 3103 etc.

In addition, the display shown in FIG. 19C has small and medium-sized orlarge-sized screen, for example a size of 5 to 20 inches. Further, tomanufacture the display part with such sizes, it is preferable tomass-produce by gang printing by using a substrate with one meter on aside.

As described above, the applicable range of the present invention isvery large, and the invention can be applied to electronic apparatusesof various areas. Note that the electronic devices of this Example canbe achieved by utilizing any combination of constitutions in Examples 1to 9.

What is claimed is:
 1. A semiconductor device comprising: a firstsubstrate having flexibility; an oxide layer over the first substrate; ametal material stuck on a surface of the oxide layer, wherein the metalmaterial is stuck on the first substrate side of the oxide layer; alayer containing an element over the oxide layer; and a first sealingfilm over the layer containing the element.
 2. The semiconductor deviceaccording to claim 1 further comprising a second sealing film betweenthe first substrate and the oxide layer.
 3. The semiconductor deviceaccording to claim 1 further comprising a second substrate havingflexibility over the first sealing film.
 4. The semiconductor deviceaccording to claim 3, wherein the first substrate is a plasticsubstrate, and wherein the second substrate is a plastic substrate. 5.The semiconductor device according to claim 1, wherein the element is atransistor.
 6. The semiconductor device according to claim 1, whereinthe element is a light emitting element.
 7. The semiconductor deviceaccording to claim 1, wherein the first sealing film comprises a filmcontaining inorganic matters.
 8. The semiconductor device according toclaim 1, wherein the first sealing film comprises a film containingresin.
 9. The semiconductor device according to claim 1, wherein themetal material comprises an element selected from the group consistingof W, Ti, Al, Ta, Mo, Cu, Cr, Nd, Fe, Ni, Co, Zr, Zn, Ru, Rh, Pd, Os, Irand Pt, or an alloy material or a compound material which comprises theelement as a main component.
 10. A semiconductor device comprising: afirst substrate having flexibility; a sealing film over the firstsubstrate; an oxide layer over the sealing film; a metal material stuckon a surface of the oxide layer, wherein the metal material is stuck onthe first substrate side of the oxide layer; and a layer containing anelement over the oxide layer.
 11. The semiconductor device according toclaim 10 further comprising a second substrate having flexibility overthe layer containing the element.
 12. The semiconductor device accordingto claim 11, wherein the first substrate is a plastic substrate, andwherein the second substrate is a plastic substrate.
 13. Thesemiconductor device according to claim 10, wherein the element is atransistor.
 14. The semiconductor device according to claim 10, whereinthe element is a light emitting element.
 15. The semiconductor deviceaccording to claim 10, wherein the sealing film comprises a filmcontaining inorganic matters.
 16. The semiconductor device according toclaim 10, wherein the sealing film comprises a film containing resin.17. The semiconductor device according to claim 10, wherein the metalmaterial comprises an element selected from the group consisting of W,Ti, Al, Ta, Mo, Cu, Cr, Nd, Fe, Ni, Co, Zr, Zn, Ru, Rh, Pd, Os, Ir andPt, or an alloy material or a compound material which comprises theelement as a main component.